OpenLLM-France/wikimedia huggingface dataset:
# AP United States History/The Planting of English America

During the 1600s and early 1700s, England established its first successful colonies in North America. This period is known as the planting of English America. There were several key reasons why the English were interested in colonizing North America at this time.
First, England wanted to gain economic benefits from the new land. The English hoped to find gold and silver, as the Spanish had in Mexico and South America. They also planned to grow valuable cash crops, like tobacco, which could be sold back in England. Making money was a major motivator for English colonization.
Second, England was in competition with other European powers like France, Spain, and the Netherlands. By planting colonies, England could lay claim to North American territory before other countries did. The more land England controlled, the more powerful they were. Colonies boosted England's global influence and prestige.
Third, religious tensions in England fueled migration to America. Groups like the Puritans, who were persecuted for their religious beliefs, sought refuge in the new colonies. They hoped to build communities where they could practice their faith freely. This religious freedom was a big draw for many English settlers.
The first successful English colony was Jamestown, founded in Virginia in 1607. Early Jamestown nearly failed due to disease, famine, and conflict with local Native American tribes. But once the colonists discovered tobacco as a profitable export crop, the settlement began to thrive.
Other important early colonies included Plymouth, Massachusetts, founded by the Pilgrims in 1620, and the Massachusetts Bay Colony, started by the Puritans in 1630. Over time, England established control over the entire eastern seaboard of North America from Maine down to Georgia.
While motivated by economics, power, and religion, the planting of English America ultimately led to the development of what would one day become the United States. This period planted the seeds that grew into a new nation.
# Technological Tips and Tricks

This module contains list of technological tips and tricks that their authors have found useful for language learning. Links are provided to other modules in the Wikibook with more information.

## Writing

* For a free, quick, accessible multilingual spelling checker, use Gmail to compose a message and use the spelling checker in the upper right corner of the message window.
* Online translator - Receive Instant translation for more than 30 languages

## Interaction
### Google Mail (Gmail) and Google Talk

* Google Mail (Gmail) combined with Google Talk provides an integrated environment for e-mail, text chat, and audio chat interaction with features of particular use for language learners.
** Gmail provides large data storage (over 2.7 GB) and multilingual spelling checker.
** Google Talk provides
*** Text chat with archiving of text chat episodes in the "Chat" mailbox (compatible with Macintosh iChat text chat and other Jabber text chat software).
*** Audio chat (Windows only)
*** Online status of contacts

### Skype

* To talk with native speakers of the language you are learning, use the Skype directory to find "Skype me" users searching the desired language and/or country. You can look at their profile before making contact. Skype users in "Skype me" mode are online users who are currently looking for new Skype contacts.

## Listening

* speed control
* How to deal with "redundancy" when listening? Redundancy includes rephrasing, repetitions, elaborations, and little insertions of "I mean" and "you know." Although they make the statements not so fluent, we can use them to help understanding. They help the hearer to process meaning by offering more time and information.

## Reading

* Google Word Translator for English into x, y, z, . . . WordChamp for x, y , z into English.
* WordChamp for multingual mouse-over translations, including other languages into English.
* Ultralingua for clickable translation from multiple languages to multiple languages
# A History of the British Monarchy/Norman Rulers/William I

William the First, or William the Conqueror was the first Norman king of England. He invaded England in 1066, after winning the Battle of Hastings. He was also the duke of Normandy. He had several children, including the next duke of Normandy and two of the English kings. He was married to Matilda of Flanders. He was an illegitimate son of Robots the Magnificent and Herleva of Falaise. He was born in 1028 and died on the 9 September 1087, when he was aged about 59.
# A History of the British Monarchy/Saxon Rulers/Edmund I the Elder

Edward the Elder succeeded Alfred the great as the King of the Anglo-Saxons.
As a son of a king, Edward was an ætheling, a prince of the royal house who was eligible for kingship. Even though he had the advantage of being the eldest son of the reigning king, his accession was not assured as he had cousins who had a strong claim to the throne. Æthelhelm and Æthelwold were sons of Æthelred, Alfred's older brother and predecessor as king, but they had been passed over because they were infants when their father died. Asser gives more information about Edward's childhood and youth than is known about other Anglo-Saxon princes, providing details about the training of a prince in a period of Carolingian influence, and Yorke suggest that we may know so much due to Alfred's efforts to portray his son as the most throneworthy ætheling.
# A History of the British Monarchy/Hanoverarian Rulers

The House of Hanover came to the throne in 1714 when Queen Anne died without living children.
Though more distant than some other possible successors, George of Hanover, great grandson of James I and VI (Stuart) was the nearest living non-Catholic candidate. Catholics have been barred from the British throne by the Act of Settlement in 1701.

## Hanovarian Rulers of Great Britain

* George I (r. 1714 - 1727)
* George II (r. 1727 - 1760)
* George III (r. 1760 - 1820)
* George IV (r. 1820 - 1830)
* William IV (r. 1830 - 1837)
* Victoria (r. 1837 - 1901)
# A History of the British Monarchy/Plantagenet Rulers

The first Plantagenet Rulers of England can be considered to be the Angevin kings, though the name was not adopted by the family until Richard of York in the 15th century, but has been retroactively applied.
The last Angevin Ruler, John, lost most of the continental empire that had given the House of Anjou that name. His son, Henry III, is therefore considered here the first Plantagenet rather than an Angevin.

## Plantagenet Rulers of England

* Henry III (r. 1216 - 1272)
* Edward I (r. 1272 - 1307)
* Edward II (r. 1307 - 1327)
* Edward III (r. 1327 - 1377)
* Richard II (r. 1377 - 1399)
# A History of the British Monarchy/Saxon Rulers
## Saxon Rulers

The Saxon Rulers began with The House of Wessex. It is the oldest known Ruling "House", AKA A Ruling Family. The first king of the Wessex House and of England was named Egbert. He was born between 770 and 780. He was the son of Ealhmund, King of Kent. Ealhmund was himself the son of Eafa, King of Wessex, by a Kentish princess. The House of Wessex boasted of a descent from no less a personage than the great Woden himself. The Anglo Saxon Chronicle records the descent of Egbert from Cerdic, a Saxon invader who landed on the south coast in 495.
The Saxon rulers' reign ended in 1066 with the reign of Harold II.
    Egbert
    Ethelwulf
    Ethelbald
    Ethelbert
    Ethelred I
    Alfred the Great
    Edward the Elder
    Athelstan
    Edmund I the Elder
    Edred
    Edwy the Fair
    Edgar the Peaceful
    Edward the Martyr
    Ethelred II
    Edmund II
    St. Edward the Confessor
    Harold II
# A History of the British Monarchy/Lancastrian Rulers

The House of Lancaster was descended from John of Gaunt, third son of Edward III. Henry IV ousted his cousin Richard II (descended from Edward III's second son) and Richard's son Edmund Mortimer to seize the throne.
The reign of Henry VI was interrupted during the Wars of the Roses.

## Lancastrian Rulers of England

* Henry IV (r. 1399 - 1413)
* Henry V (r. 1413 - 1422)
* Henry VI (r. 1422 - 1461, and 1470 - 1471)
# A History of the British Monarchy/Saxe-Coburg-Gotha Rulers

The House of Saxe-Coburg Gotha was made the royal house in 1901 when Queen Victoria died and Edward VII (Albert Edward), who used his fathers family name and herediatary house as his own.
Edward VII, Queen Victoria's eldest son, was the first Saxe-Coburg-Gotha monarch. He ascended on 22 January 1901. In the beginning of his reign, he reintroduced rituals such as the State Opening of Parliament that his mother had eliminated. In 1904, a remarkable achievement, the Entente Cordiale, allying Britain and France occurred and ended the "Splendid Isolation" of Britain from Continental politics. Due to this, Edward is popularly known as the Peacemaker. His later reign was marked by the constitutional crisis over the People's Budget proposed by Prime Minister H.H. Asquith. The budget introduced by the Commons was vetoed by the Lords in November 1909, causing an election in January 1910. The new Parliament made plans to remove the Lords' veto power, and did with the passage of the Parliament Act of 1911. However, Edward did not live to see this, dying on 6 May 1910 at Buckingham Palace. His funeral on 20 May was attended by nine European monarchs, almost all related to the man known as the "Uncle of Europe".
Edward was succeeded by his son George, who become George V. George inherited the political situation his father had left behind. Negotiations over the budget eventually broke down, and he was forced to call an election in December 1910. In 1911, the Parliament Act was passed removing the power of the Lords, with few exceptions, to veto bills. The next crisis concerned Irish Home Rule. Legislation was introduced to grant this, but the Conservatives and the Unionists were staunchly opposed. In July 1914, George held a meeting at Buckingham Palace between the political parties to negotiate over the issue. The negotiations were fruitless, but on 18 September the Home Rule Bill was granted assent. However, it was delayed due to World War I. This was a personal crisis for George, as many of his relatives were German and supported Kaiser Wilhelm II, the symbol of German aggression to the British people and George's first cousin. Thus, on 17 July 1917, George, by Royal Proclamation, changed the Royal House and family to be "Windsor" rather than "Saxe-Coburg-Gotha", due to the Germanic reference. He also asked all members of the Extended Royal Family to relinquish their Germanic titles, which was completed by the Duke of Teck (Marquess of Cambridges), Prince of Battenberg (Marquess of Milford Haven) and Count von Gleichen.
# A History of the British Monarchy/Norman Rulers

The Norman ruler of England began in 1066 when William, Duke of Normandy, invaded and defeated Harald Godwinson. This was the last successful invasion of England, and all English monarchs since have descended from him.
The end of the dynasty is a bit blurred. Matilda was the daughter of Henry I. When his son (William Adelin, Matilda's brother) died in 1120, Henry I put forward Matilda as his heir, but was unsuccessful.
Stephen was his nephew, and as the nearest male heir to Henry I, he was installed on the throne at Henry's death. Matilda and her supporters considered this a usurpation and a long civil war, called The Anarchy, was fought between 1135 and 1153. The Treaty of Westminster ended the fighting, and Matilda's son, Henry FitzEmpress was designated as Stephen's heir.
While technically still a Norman, Henry FitzEmpress founded the Plantagenet dynasty as Henry II.

## The Norman rulers of England

* William I the Conqueror (r. 1066 – 1087)
* William II (r. 1087 – 1100)
* Henry I (r. 1100 – 1135)
* Matilda, also called Maud (claimed: 1135 – 1153)
* Stephen (House of Blois) (r. 1135 – 1154)

## External Links

* [The Anarchy] at Wikipedia
# Theorem

Let n be a positive integer. Let x be an integer relatively prime to n Let φ(n) = number of positive integers less than and relatively prime to n
    $x^{\varphi (n)}\equiv 1{\pmod {n}}$

# Proof

$\mathbb {Z} /n^{\times }$ with multiplication mod n is a Group of positive integers less than and relatively prime to integer n.
φ(n) = o($\mathbb {Z} /n^{\times }$)
Let X be the cyclic subgroup of $\mathbb {Z} /n^{\times }$ generated by x mod n.
As X is subgroup of $\mathbb {Z} /n^{\times }$
    0. o(X) divides o($\mathbb {Z} /n^{\times }$)
    1. o($\mathbb {Z} /n^{\times }$) / o(X) is an integer
    2. $x^{\varphi (n)}=x^{o(\mathbb {Z} /n^{\times })}=x^{o(X)o(\mathbb {Z} /n^{\times })/o(X)}=[x^{o(X)}]^{o(\mathbb {Z} /n^{\times })/o(X)}=e^{o(\mathbb {Z} /n^{\times })/o(X)}=e$
# Theorem

Let g be any element of group G.
Let H be a subgroup of G. Let o(H) be order of group H.
Let gH be coset of H by g. Let o(gH) be order of gH
    o(H) = o(gH)

# Proof

Overview: A bijection between H and gH would show their orders are equal.
    0. Define ${\begin{aligned}f\colon H&\to gH\\h&\mapsto gh\end{aligned}}$

## f is surjective

    1. f is surjective by definition of gH and f.

## f is injective

    2. Choose ${\color {Blue}h_{1}},{\color {OliveGreen}h_{2}}\in H$ such that $f({\color {Blue}h_{1}})=f({\color {OliveGreen}h_{2}})$ 3. $g{\color {Blue}h_{1}}=g{\color {OliveGreen}h_{2}}$ 0. 4. $g,{\color {Blue}h_{1}},{\color {OliveGreen}h_{2}}\in G$ ${\color {Blue}h_{1}},{\color {OliveGreen}h_{2}}\in H$, and subgroup $H\subseteq G$ 5. ${\color {Blue}h_{1}}={\color {OliveGreen}h_{2}}$ 3. and cancelation justified by 4 on G

## o(H) = o(gH)

As f is surjective and injective,
       6. f is a bijection from H to gH
       7. Such bijection shows o(H) = o(gH)
# Abstract Algebra/Group Theory/Subgroup/Cyclic Subgroup/Definition of a Cyclic Subgroup

Let G be a Group. Let g be an element of G.
The Cyclic Subgroup generated by g is:
    $\forall \;g\in G:\langle g\rangle =\lbrace g^{n}\;|\;n\in \mathbb {Z} \rbrace$
       where $g^{n}={\begin{cases}\underbrace {g\ast g\cdots \ast g} _{n},&n\in \mathbb {Z} ,n\geq 0\\\underbrace {g^{-1}\ast g^{-1}\cdots \ast g^{-1}} _{-n},&n\in \mathbb {Z} ,n<0\end{cases}}$
       By induction, we have:
          $\forall g\in G:\forall n,m\in \mathbb {Z} :g^{m+n}=g^{m}\ast g^{n}{\text{ and }}g^{mn}=[g^{m}]^{n}$
# Abstract Algebra/Group Theory/Subgroup/Definition of a Subgroup

Let G be a group with binary operation $\ast$
    Subgroup H of Group G
      * is a group
      * is a subset of G
      * shares $\ast$ with G
# Theorem

Let H be a subgroup of group G.
Let o(H), o(G), be orders of H, G respectively
    o(H) divides o(G)

# Proof

As H is Subgroup of G,
    1. All Left Cosets of H partitions G.
    2. Each of such partitions is one of the Cosets of H.
    3. Any coset of H has the same order as H does.
    4. Thus, o(H) divides o(G)
# Abstract Algebra/Group Theory/Subgroup/Normal Subgroup/Definition of a Normal Subgroup

A normal subgroup is a subgroup H of a group G that satisfies
    $\forall \;g\in G:gHg^{-1}=H$
    where $gHg^{-1}=\lbrace g\ast h\ast g^{-1}|h\in H\rbrace$

# Equivalent Definition

* $\forall \;g\in G,h\in H:g\ast h\ast g^{-1}\in H$

## Proof

    $gHg^{-1}\subseteq H$ by this definition
    $H\subseteq gHg^{-1}$
    0. Choose $g\in G,x\in H$ 1. $g^{-1}\in G$ 2. $g^{-1}\ast x\ast [g^{-1}]^{-1}\in H$ by this definition 3. $g\ast (g^{-1}\ast x\ast [g^{-1}]^{-1})\ast g^{-1}\in gHg^{-1}$ 4. $h\in gHg^{-1}$
# Theorem

Let H be subgroup of Group G. Let $\ast$ be the binary operation of both H and G
    H and G shares identity

# Proof

    0. Let e$_H$, e$_G$ be identities of H and G respectively. 1. ${\color {OliveGreen}e_{H}}\ast {\color {OliveGreen}e_{H}}={\color {OliveGreen}e_{H}}$ e$_H$ is identity of H (usage 1, 3) 2. ${\color {OliveGreen}e_{H}}\in H$ e$_H$ is identity of H (usage 1) 3. $H\subseteq G$ H is subgroup of G 4. ${\color {OliveGreen}e_{H}}\in G$ 2. and 3. 5. ${\color {OliveGreen}e_{H}}\ast {\color {Blue}e_{G}}={\color {OliveGreen}e_{H}}$ 4. and e$_G$ is identity of G (usage 3) 6. ${\color {OliveGreen}e_{H}}\ast {\color {Blue}e_{G}}={\color {OliveGreen}e_{H}}\ast {\color {OliveGreen}e_{H}}$ 1. and 5. 7. ${\color {Blue}e_{G}}={\color {OliveGreen}e_{H}}$ cancellation on group G

# Usages

* If H is subgroup of group G, identity of G is identity of H.
* If H is subgroup of group G, identity of G is in H.
# Theorem

Define Order of an Element g of Finite Group G:
    o(g) = the least positive integer n such that g$^n$ = e
Define Order of a Cyclic Subgroup generated by g:
    $o(\langle g\rangle )$ = # elements in $\langle g\rangle$
       o(g) = $o(\langle g\rangle )$

# Proof

By diagram,
    0. $g^{o(\langle g\rangle )}=e=g^{o(g)}$.
    1. Let n = o(g), and m = $o(\langle g\rangle )$
    2. g$^n$ = g$^m$
    3. g$^{n–m}$ = e
    4. Let n – m = sn + r where r, n, s are integers and 0 ≤ s < n.
    5. g$^{sn+r}$ = e
    6. $[g^{n}]^{s}\ast g^{r}=e$
By definition of n = o(g)
    7. g$^r$ = e
As n is the least that makes g$^n$ = e and 0 ≤ r < n.
    8. r = 0
Lemma: Let $k,m\in \mathbb {Z}$. $g^{k}=g^{m}$ if and only if $k\equiv m(\,{\bmod {\ }}o(g))$.
Proof: Let $n=o(g)$. $g^{k}=g^{m}$ if and only if $g^{k-m}=e$. By Euclidean division: $k-m=qn+r$, some integers $q,r$ with $0\leq r<n$. We have $g^{r}=g^{k-m-qn}=g^{k-m}{(g^{n})}^{-q}=g^{k-m}$, hence $g^{r}=e$ if and only if $g^{k}=g^{m}$. But $g^{r}=e$ if and only if $r=0$ (i.e. if and only if $n\mid k-n$), since, by definition, $n=o(g)$ is the least positive integer satisfying $g^{n}=e$. Hence the result. $\square$
By definition: $\langle g\rangle =\{g^{r}:r\in \mathbb {Z} \}$. Therefore, $g,g^{2},\ldots ,g^{n}$ (where $n=o(g)$) all lie in $\langle g\rangle$ – furthermore, by lemma above, these are pairwise distinct. Finally, any element of the form $g^{r}$, $r\in \mathbb {Z}$ equals one of $g,g^{2},\ldots ,g^{n}$ (again by lemma). We conclude that $g,g^{2},\ldots ,g^{n}$ are precisely the elements of $\langle g\rangle$, so $o(\langle g\rangle )=n=o(g)$, as required. - Q.E.D. -
# Theorem

Let H$_1$, H$_2$, ... H$_n$ be subgroups of Group G with operation $\ast$
    $H_{1}\cap H_{2}\cap \cdots \cap H_{n}$ with $\ast$ is a subgroup of Group G

# $\color {RawSienna}(H_{1}\cap H_{2})\subseteq G$

    1. $H_{1}\subseteq G$ H$_1$ is subgroup of G 2. $H_{2}\subseteq G$ H$_2$ is subgroup of G 3. $(H_{1}\cap H_{2})\subseteq G$ 1. and 2.

# $\color {RawSienna}H_{1}\cap H_{2}$ with $\color {RawSienna}\ast$ is a Group
## Closure

       4. Choose $x,y\in (H_{1}\cap H_{2})$ 5. $x\ast y\in H_{1}$ closure of H$_1$ 6. $x\ast y\in H_{2}$ closure of H$_2$ 7. $x\ast y\in (H_{1}\cap H_{2})$ 5. and 6.

## Associativity

       8. $\ast$ is associative on G. Group G's operation is $\ast$ 9. $(H_{1}\cap H_{2})\subseteq G$ 3. 10. $\ast$ is associative on $(H_{1}\cap H_{2})$ 8. and 9.

## Identity

       11. $e_{G}\in H_{1}$ and $e_{G}\in H_{2}$ Subgroup H$_1$ and H$_2$ inherit identity from G 12. $\forall g\in G:e_{G}\ast g=g\ast e_{G}=g$ e$_G$ is identity of G, 13. $\forall \;g\in (H_{1}\cap H_{2}):e_{G}\ast g=g\ast e_{G}=g$ $(H_{1}\cap H_{2})\subseteq G$ and 9. 14. $(H_{1}\cap H_{2})$ has identity e$_G$ definition of identity

## Inverse

       15. Choose $g\in (H_{1}\cap H_{2})\subseteq G$ 16. $g\in H_{1}$, $g\in H_{2}$, and $g\in G$ 17. g$_{H1}$$^{−1}$ in H1, and g$_{H2}$$^{−1}$ in H2. G, H$_1$, and H$_2$ are groups 18. $g_{H1}^{-1}\in G$ $H_{1}\subseteq G$ 19. $g_{H1}^{-1}\ast g=g\ast g_{H1}^{-1}=e_{G}$ G and H1 shares identity e 20. g$_{H1}$$^{−1}$ is inverse of g in G 19. and definition of inverse 21. Let g$_G$$^{−1}$ be inverse of g has in G 22. g$_G$$^{−1}$ = g$_{H1}$$^{−1}$ inverse is unique 22. g$_G$$^{−1}$ = g$_{H2}$$^{−1}$ similar to 21. 23. $g^{-1}=g_{H1}^{-1}=g_{H2}^{-1}\in (H_{1}\cap H_{2})$ 24. g has inverse g$^{−1}$ in $(H_{1}\cap H_{2})$
# A-level Physics/Forces, Fields and Energy/Further dynamics

From last year, you should remember kinematics and dynamics, the branch of physics that relates to the motion of objects. We will now expand on this and have a look at what happens when two objects collide, the concept of momentum, and we will take a closer look at Newton's three laws of motion.

## Momentum

If you have seen collisions involving two objects, you may have noticed that the velocity of one object seems to be passed to the other object. You may also have noticed that heavier objects seem to pass more velocity on to smaller objects, whereas smaller objects seem to pass less velocity to more massive ones.
What is in fact happening is that momentum is being conserved. Momentum is the product of an objects mass and velocity, or $p=mv$. This means that, after a collision, an object that is heavier will have a lower velocity than a lighter object in its place, and vice versa. Momentum is conserved for all collisions. The principle of the conservation of momentum states that:
Within a closed system, the total momentum in any specified direction remains constant.
Momentum is a vector quantity and has the units $kg\,m\,s^{-1}$ or $Ns$ (Newton-seconds) in the SI system.

## Collisions

Since momentum is conserved, the momentum before a collision is equal to the momentum after a collision. You can use this fact to solve problems involving collisions.
${\begin{alignedat}{2}Before&=After\\m_{1}u_{1}+m_{2}u_{2}&=m_{1}v_{1}+m_{2}v_{2}\\\end{alignedat}}$
For instance, a ball is moving at 3 m/s with mass 3 kg. It hits another ball with mass 1 kg moving at 2 m/s; the two balls collide and the second ball rebounds at 4 m/s. Find the velocity at which ball 1 is moving:
${\begin{alignedat}{2}Before&=After\\m_{1}u_{1}+m_{2}u_{2}&=m_{1}v_{1}+m_{2}v_{2}\\3\times 3+2\times 1&=3v+1\times 4\\11&=3v+4\\11-4&=3v\\7&=3v\\v&={\frac {7}{3}}\\\end{alignedat}}$
So the velocity at which ball 1 is moving after the collision is 2.3 m/s (7/3)m/s 1

## Newton's laws of motion
### Newton's first law of motion

A body stays at rest or continues to move at constant velocity unless a resultant force acts on it

### Newton's second law of motion

Originally, you learnt this to be:
For an object with constant mass, its acceleration is proportional to the force producing the acceleration, and is in the direction of the force.
However, since you now know that a force changes the rate of change of momentum of an object, we can use a more accurate interpretation of Newton's second law:
The rate of change of momentum of a body is proportional to the resultant force acting on the body and takes place in the direction of the resultant force.

### Newton's third law of motion

If body A exerts a force on body B, then body B will exert a force of the same type that is equal in magnitude and opposite in direction on body A..
# A-level Physics (Advancing Physics)/Binding Energy/Worked Solutions

1. Deuterium (an isotope of Hydrogen with an extra neutron) has a nuclear mass of 2.01355321270 u. What is its binding energy?
Total mass of neutron and proton is 1.00727647 + 1.00866492 = 2.01594139 u
Mass defect = 2.01594139 - 2.01355321270 = 0.002388178 u = 3.965662187 x 10$^{−30}$ kg
$E=\Delta mc^{2}=3.57\times 10^{-13}{\mbox{ J }}=2.23{\mbox{ MeV}}$
2. Uranium-235 has a nuclear mass of 235.0439299 u. It contains 92 protons. What is its binding energy?
235 - 92 = 143 neutrons
Total mass of baryons is (92 x 1.00727647) + (143 x 1.00866492) = 236.9085188 u
Mass defect = 236.9085188 - 235.0439299 = 1.8645889 u = 3.096222181 x 10$^{−27}$ kg
$E=\Delta mc^{2}=2.79\times 10^{-10}{\mbox{ J }}=1.74{\mbox{ GeV}}$
3. How would you expect H-2 and U-235 to be used in nuclear reactors? Why?
H-2 is used in experimental fusion reactors, since it has a smaller nucleus than Iron-56.
U-235 is used in fission reactors, since it has a much larger nucleus than Iron-56.