Answer the following question given this paragraph: It can be really exciting to explore a big underground cave like the one in this picture. Do you know how caves form? Believe it or not, water is the answer. Water slowly dissolves rocks, especially certain types of rocks such as limestone. How does something as mild and harmless as water cause hard rocks to dissolve? In this chapter, you'll find out. Q: Caves form over time when what causes rocks like limestone to dissolve? Choices: - weather - acid - air - water A:
water
Answer the following question given this paragraph: The plasma membrane controls what moves inside and outside the cell. Q: What controls what moves inside and outside the cell? Choices: - nucleus - golgi apparatus - mitochondria - the plasma membrane A:
the plasma membrane
Q: Answer the following question given this paragraph: Nucleic acids consist of chains of small molecules called nucleotides, which are held together by covalent bonds. The structure of a nucleotide is shown in the Figure below . Each nucleotide consists of:. Q: Chains of small molecules called nucleotides make up what? Choices: - chromosomes - peptides - proteins - nucleic acids A:
A: nucleic acids
Question: Answer the following question given this paragraph: Did you ever hear an echo of your own voice? An echo occurs when sound waves bounce back from a surface that they can't pass through. The woman pictured here is trying to create an echo by shouting toward a large building. When the sound waves strike the wall of the building, most of them bounce back toward the woman, and she hears an echo of her voice. An echo is just one example of how waves interact with matter. Q: What is heard when sound waves bounce back from a surface that they can't pass through? Choices: - radio - ultrasound - loop - echo A:
Answer: echo
*Question*
Answer the following question given this paragraph: The process in which an atom becomes an ion is called ionization. It may occur when atoms are exposed to high levels of radiation. The radiation may give their outer electrons enough energy to escape from the attraction of the positive nucleus. However, most ions form when atoms transfer electrons to or from other atoms or molecules. For example, sodium atoms may transfer electrons to chlorine atoms. This forms positive sodium ions (Na + ) and negative chloride ions (Cl - ). You can see an animation of this process at the URL below. Q: What is the process in which an atom becomes an ion known as? Choices: - electrification - evaporation - oxidation - ionization A:
**Answer**
ionization
Q: Answer the following question given this paragraph: Acids have some properties in common. They turn litmus, a plant extract, red. They react with some metals to give off H2 gas. They react with carbonate and hydrogen carbonate salts to give off CO2 gas. Acids that are ingested typically have a sour, sharp taste. (The name acid comes from the Latin word acidus, meaning "sour. ") Bases also have some properties in common. They are slippery to the touch, turn litmus blue, and have a bitter flavor if ingested. Acids and bases have another property: they react with each other to make water and an ionic compound called a salt. A salt, in chemistry, is any ionic compound made by combining an acid with a base. A reaction between an acid and a base is called a neutralization reaction and can be represented as follows: acid + base H2O + salt The stoichiometry of the balanced chemical equation depends on the number of H+ions in the acid and the number of OH ions in the base. Q: What type of ionic compound is formed from acid and bases reacting with each other? Choices: - isolated - common - dry - salt A:
A: salt