Answer the following question given this paragraph: Nitrates, salts of nitric acid, form when metals, oxides, hydroxides, or carbonates react with nitric acid. Most nitrates are soluble in water; indeed, one of the significant uses of nitric acid is to prepare soluble metal nitrates. Nitric acid finds extensive use in the laboratory and in chemical industries as a strong acid and strong oxidizing agent. It is important in the manufacture of explosives, dyes, plastics, and drugs. Salts of nitric acid (nitrates) are valuable as fertilizers. Gunpowder is a mixture of potassium nitrate, sulfur, and charcoal. The reaction of N2O3 with water gives a pale blue solution of nitrous acid, HNO2. However, HNO2 (shown in Figure 18.51) is easier to prepare by the addition of an acid to a solution of nitrite; nitrous acid is a weak acid, so the nitrite ion is basic in aqueous solution: NO 2 (aq) + H 3 O +(aq) HNO 2(aq) + H 2 O(l) Nitrous acid is very unstable and exists only in solution. It disproportionates slowly at room temperature (rapidly when heated) into nitric acid and nitric oxide. Nitrous acid is an active oxidizing agent with strong reducing agents, and strong oxidizing agents oxidize it to nitric acid. Q: What is a mixture of potassium nitrate, sulfur, and charcoal? Choices: - gasoline - cyanide - TNT - gunpowder A:
gunpowder
Answer the following question given this paragraph: Cell division is just one of several stages that a cell goes through during its lifetime. The cell cycle is a repeating series of events that include growth, DNA synthesis, and cell division. The cell cycle in prokaryotes is quite simple: the cell grows, its DNA replicates, and the cell divides. In eukaryotes, the cell cycle is more complicated. Q: What is defined as a repeating series of events that include growth, dna synthesis, and cell division? Choices: - photosynthesis - meiosis - puberty - cell cycle A:
cell cycle
Q: Answer the following question given this paragraph: Winter solstice for the Northern Hemisphere happens on December 21 or 22. The North Pole of Earth's axis points away from the Sun ( Figure below ). Light from the Sun is spread out over a larger area. With fewer daylight hours in winter, there is also less time for the Sun to warm the area. When it is winter in the Northern Hemisphere, it is summer in the Southern Hemisphere. Q: What season is it in the southern hemisphere when it's winter in the northern? Choices: - Winter - Spring - autumn - summer A:
A: summer
Question: Answer the following question given this paragraph: Abrasion is another type of mechanical weathering. With abrasion, one rock bumps against another rock. Gravity causes abrasion as a rock tumbles down a slope. Moving water causes abrasion it moves rocks so that they bump against one another ( Figure below ). Strong winds cause abrasion by blasting sand against rock surfaces. Finally, the ice in glaciers cause abrasion. Pieces of rock embedded in ice at the bottom of a glacier scrape against the rock below. If you have ever collected beach glass or pebbles from a stream, you have witnessed the work of abrasion. Q: What kind of weathering is abrasion? Choices: - molecular - electromagnetic - natural - mechanical A:
Answer: mechanical
*Question*
Answer the following question given this paragraph: Q: What is the second state of photosynthesis? Choices: - Phillip cycle - glover cycle - morton cycle - calvin cycle A:
**Answer**
calvin cycle
*Question*
Answer the following question given this paragraph: Covalent Molecules and Compounds Just as an atom is the simplest unit that has the fundamental chemical properties of an element, a molecule is the simplest unit that has the fundamental chemical properties of a covalent compound. Some pure elements exist as covalent molecules. Hydrogen, nitrogen, oxygen, and the halogens occur naturally. Q: What is the simplest unit that has the fundamental chemical properties of an element? Choices: - neutron - nucleus - cell - atom A:
**Answer**
atom