*Question*
Answer the following question given this paragraph: Summary The atoms in chemical compounds are held together by attractive electrostatic interactions known as chemical bonds. Ionic compounds contain positively and negatively charged ions in a ratio that results in an overall charge of zero. The ions are held together in a regular spatial arrangement by electrostatic forces. Mostcovalent compounds consist of molecules, groups of atoms in which one or more pairs of electrons are shared by at least two atoms to form a covalent bond. The atoms in molecules are held together by the electrostatic attractionbetween the positively charged nuclei of the bonded atoms and the negatively charged electrons shared by the nuclei. The molecular formula of a covalent compound gives the types and numbers of atoms present. Compounds that contain predominantly carbon and hydrogen are called organic compounds, whereas compounds that consist primarily of elements other than carbon and hydrogen areinorganic compounds. Diatomic molecules contain two atoms, andpolyatomic molecules contain more than two. A structural formula indicates the composition and approximate structure and shape of a molecule. Single bonds, double bonds, and triple bonds are covalent bonds in which one, two, and three pairs of electrons, respectively, are shared between two Saylor URL: http://www. saylor. org/books. Q: What kind of compounds contain positively and negatively charged ions in a ratio that results in an overall charge of zero? Choices: - neutral compounds - zero charged compunds - zeronic ions - ionic compounds A:
**Answer**
ionic compounds

*Question*
Answer the following question given this paragraph: A lever is a simple machine consisting of a bar that rotates around a fixed point. The fixed point of a lever is called the fulcrum. Like other machines, a lever makes work easier by changing the force applied to the machine or the distance over which the force is applied. For a video introduction to levers using skateboards as examples, go to this URL:. Q: What do you call the fixed point of a lever? Choices: - base - caliper - apex - fulcrum A:
**Answer**
fulcrum

*Question*
Answer the following question given this paragraph: Density describes how much matter is in a certain amount of space. Substances that have more matter packed into a given space have higher densities. The water in a drinking glass has the same density as the water in a bathtub or swimming pool. All substances have characteristic densities, which does not depend on how much of a substance you have. Q: What describes how much matter is in a certain amount of space? Choices: - volume - mass - viscosity - density A:
**Answer**
density

*Question*
Answer the following question given this paragraph: Q: Each atom has a required number of what? Choices: - matrix bonds - accretion bonds - acceleration bonds - covalent bonds A:
**Answer**
covalent bonds