Answer the following question given this paragraph: The Behavior of Electrons In the human body, atoms do not exist as independent entities. Rather, they are constantly reacting with other atoms to form and to break down more complex substances. To fully understand anatomy and physiology you must grasp how atoms participate in such reactions. The key is understanding the behavior of electrons. Although electrons do not follow rigid orbits a set distance away from the atom's nucleus, they do tend to stay within certain regions of space called electron shells. An electron shell is a layer of electrons that encircle the nucleus at a distinct energy level. The atoms of the elements found in the human body have from one to five electron shells, and all electron shells hold eight electrons except the first shell, which can only hold two. This configuration of electron shells is the same for all atoms. The precise number of shells depends on the number of electrons in the atom. Hydrogen and helium have just one and two electrons, respectively. If you take a look at the periodic table of the elements, you will notice that hydrogen and helium are placed alone on either sides of the top row; they are the only elements that have just one electron shell (Figure 2.7). A second shell is necessary to hold the electrons in all elements larger than hydrogen and helium. Lithium (Li), whose atomic number is 3, has three electrons. Two of these fill the first electron shell, and the third spills over into a second shell. The second electron shell can accommodate as many as eight electrons. Carbon, with its six electrons, entirely fills its first shell, and half-fills its second. With ten electrons, neon (Ne) entirely fills its two electron shells. Again, a look at the periodic table reveals that all of the elements in the second row, from lithium to neon, have just two electron shells. Atoms with more than ten electrons require more than two shells. These elements occupy the third and subsequent rows of the periodic table. Q: What is the layer of electrons that encircle the nucleus at a distinct energy level called? Choices: - molecular shell - vortex shell - ions shell - electron shell A:
electron shell
(Question)
Answer the following question given this paragraph: Q: What type of behaviors are triggered by pheromones in moths? Choices: - exhibit - illuminating - peculiar - courtship A:
(Answer)
courtship
Ques: Answer the following question given this paragraph: The number of waves that pass a fixed point in a given amount of time is wave frequency . Wave frequency can be measured by counting the number of crests (high points) of waves that pass the fixed point in 1 second or some other time period. The higher the number is, the greater the frequency of the waves. The SI unit for wave frequency is the hertz (Hz) , where 1 hertz equals 1 wave passing a fixed point in 1 second. The Figure below shows high-frequency and low-frequency transverse waves. You can simulate transverse waves with different frequencies at these URLs: http://phet. colorado. edu/en/simulation/wave-on-a-string and http://zonalandeducation. com/mstm/physics/waves/partsOfAWave/waveParts. htm. Q: What are waves that pass a fixed point in a given amount of time called? Choices: - tendency frequency - combination frequency - radio frequency - wave frequency A:
Ans: wave frequency
(Q).
Answer the following question given this paragraph: Amines are capable of hydrogen bonding though their boiling points are generally a bit lower than the corresponding alcohol. Methylamine and ethylamine are gases at room temperature, while larger amines are liquids. As with other organic compounds that form hydrogen bonds, water solubility is reflected in the length of the carbon chains. Smaller amines are soluble, while larger ones are less soluble. Q: As with other organic compounds that form hydrogen bonds, water solubility of amines is reflected in the length of what? Choices: - hydrocarbon bonds - complex carbohydrates - nuclei chains - carbon chains A:
(A).
carbon chains
Ques:Answer the following question given this paragraph: To keep their flight muscles well supplied with oxygen, birds evolved specialized respiratory and circulatory systems. Birds have special air sacs for storing extra air and pumping it into the lungs. They also have a relatively large heart and a rapid heart rate. These adaptations keep plenty of oxygenated blood circulating to the flight muscles. Q: Birds have a relatively large heart and a rapid what? Choices: - lifespan - blink rate - digestive process - heart rate A:

Ans:heart rate
Question: Answer the following question given this paragraph: Fungi used to be classified as plants. Now, they are known to have unique traits that set them apart from plants. For example, their cell walls contain chitin, not cellulose, and fungi absorb food rather than make their own. Below the level of the kingdom, fungi classification is controversial. Q: Once classified as plants, fungi have chitin rather than cellulose in what cell structures? Choices: - platelets - cell ridges - mitochondria - cell walls A:
Answer:
cell walls