Answer the following question given this paragraph: The halogens are among the most reactive of all elements, although reactivity declines from the top to the bottom of the halogen group. Because all halogens have seven valence electrons, they are "eager" to gain one more electron. Doing so gives them a full outer energy level, which is the most stable arrangement of electrons. Halogens often combine with alkali metals in group 1 of the periodic table. Alkali metals have just one valence electron, which they are equally "eager" to donate. Reactions involving halogens, especially halogens near the top of the group, may be explosive. You can see some examples in the video at the URL below. ( Warning: Don't try any of these reactions at home!). Q: In which order does the reactivity of halogen group decline? Choices: - bottom to top - right to left - left to right - top to bottom A:
top to bottom
(Question)
Answer the following question given this paragraph: The time scale of evolution can vary. Evolution over a short period of time at the level of the population is called microevolution. Evolution over a long period of time above the level of the species is called macroevolution. Q: Evolution over a short period of time at the level of the population is called what? Choices: - grammaticalization - redistributions - macroevolution - microevolution A:
(Answer)
microevolution
Ques: Answer the following question given this paragraph: Not getting enough minerals can cause health problems. For example, too little calcium may cause osteoporosis. This is a disease in which bones become soft and break easily. Getting too much of some minerals can also cause health problems. Many people get too much sodium. Sodium is added to most packaged foods. People often add more sodium to their food by using table salt. Too much sodium causes high blood pressure in some people. Q: What disease can too little calcium cause? Choices: - anemia - arthritis - psoriasis - osteoporosis A:
Ans: osteoporosis
(Q).
Answer the following question given this paragraph: The acidity of a solution is typically assessed experimentally by measurement of its pH. The pOH of a solution is not usually measured, as it is easily calculated from an experimentally determined pH value. The pH of a solution can be directly measured using a pH meter (Figure 14.4). Q: The acidity of a solution is typically assessed experimentally by measurement of its what? Choices: - mass - density - color - ph A:
(A).
ph
Ques:Answer the following question given this paragraph: Living things must have chemical energy from food to power life processes. Most of the chemical energy in food comes ultimately from the energy in sunlight. Q: Most of food's chemical energy ultimately comes from what source? Choices: - plants - air - minerals - sunlight A:

Ans:sunlight
Answer the following question given this paragraph: An allergy occurs when the immune system attacks a harmless substance that enters the body from the outside. A substance that causes an allergy is called an allergen. It is the immune system, not the allergen, that causes the symptoms of an allergy. Q: What occurs when the immune system attacks a harmless substance that enters the body from the outside? Choices: - panic attack - nausea - plague - allergy A:
allergy