Answer the following question given this paragraph: Rutherford's atomic model became known as the nuclear model . In the nuclear atom, the protons and neutrons, which comprise nearly all of the mass of the atom, are located in the nucleus at the center of the atom. The electrons are distributed around the nucleus and occupy most of the volume of the atom. It is worth emphasizing just how small the nucleus is compared to the rest of the atom. If we could blow up an atom to be the size of a large professional football stadium, the nucleus would be about the size of a marble. Q: In an atom, what two major types of particles are located in the nucleus? Choices: - electrons and neutrons - molecules and neutrons - ions and electrons - protons and neutrons A:
protons and neutrons
(Question)
Answer the following question given this paragraph: Ocean water normally dissolves some of the carbon dioxide in the atmosphere. The burning of fossil fuels has increased the amount of carbon dioxide in the atmosphere. As a result, ocean water is also dissolving more carbon dioxide. When carbon dioxide dissolves in water, it forms a weak acid. With higher levels of dissolved carbon dioxide in ocean water, the water becomes more acidic. This process is called ocean acidification. Q: What has the burning of fossil fuels increased in the atmosphere? Choices: - ozone - oxygen - temperature - carbon dioxide A:
(Answer)
carbon dioxide
Ques: Answer the following question given this paragraph: This is a constellation, a pattern of stars in the night sky. This constellation is called Orion. The features you can see best are his belt and sword. You can see Orion's belt in the sky from many locations. These stars are very bright. For many constellations, the stars are not near each other. They just happen to appear near each other in our sky. Q: What do you call a pattern of stars in the night sky? Choices: - Solar Systems - planets - cluster - constellation A:
Ans: constellation
(Q).
Answer the following question given this paragraph: Because the health of cells depends on maintaining the proper levels of cations in intracellular fluids, any change that affects the normal flux of metal ions across cell membranes could well cause an organism to die. Molecules that facilitate the transport of metal ions across membranes are generally called ionophores (ionplus phore from the Greek phorein, meaning "to carry"). Many ionophores are potent antibiotics that can kill or inhibit the growth of bacteria. An example isvalinomycin, a cyclic molecule with a central cavity lined with oxygen atoms (part (a) in Figure 21.14 "Valinomycin Is an Antibiotic That Functions Like an Ionophore") that is similar to the cavity of a crown ether (part (a) in Figure 13.7 "Crown Ethers and Cryptands"). Like a crown ether, valinomycin is highly selective: its affinity for K+ is about 1000 times greater than that for Na+. By increasing the flux of K+ ions into cells, valinomycin disrupts the normal K+ gradient across a cell membrane, thereby killing the cell (part (b) in Figure 21.14 "Valinomycin Is an Antibiotic That Functions Like an Ionophore"). Figure 21.14 Valinomycin Is an Antibiotic That Functions Like an Ionophore. Q: Why is it necessary to maintain proper levels of cations in intercellular fluids? Choices: - cell division - reverse homeostasis - for digestion - keep cells healthy A:
(A).
keep cells healthy
Ques:Answer the following question given this paragraph: Figure 30.4 Leaves are attached to the plant stem at areas called nodes. An internode is the stem region between two nodes. The petiole is the stalk connecting the leaf to the stem. The leaves just above the nodes arose from axillary buds. Q: What is the term for the stalk connecting a leaf to a stem? Choices: - cuticle - blades - base - petiole A:

Ans:petiole
Answer the following question given this paragraph: Sulfuric acid is produced in extremely large quantities in the United States (about 40 million tons/year). This material is manufactured by oxidizing sulfur to form sulfur trioxide. The SO 3 is then dissolved in water to form the sulfuric acid. Most of the sulfuric acid produced is used in fertilizers. This acid is also found in lead-acid car batteries. Q: What is sulfur trioxide dissolved in to form sulfuric acid? Choices: - silver - mercury - lead - water A:
water