Question

1. a horizontal row of the periodic table is usually referred to as a

a. property.
b. period.
c. group.
d. family

1. a substance that has definite shape and volume is a______.

a. solid
b. liquid
c. gas
d. plasma

1. ______ properties of matter can be determined without changing com while ______ properties of matter must change the composition of matter.

a. physical;mental
b. chemical;physical
c. physical;chemical
d. chemical;flammable

1. pure substances are further divided into elements and compounds. whi best describes the rust found on a vehicle over time?

a. a compound
b. an element
c. a mixture
d. a chemical property

1. which of the following is not an example of a compound?

a. water
b. limestone
c. salt
d. hydrogen

Explanation:

1. In the periodic table, horizontal rows are called periods. Vertical columns are groups or families.
2. Solids have a definite shape and volume due to the close - packed and ordered arrangement of their particles. Liquids have a definite volume but take the shape of their container, gases have no definite shape or volume, and plasma is an ionized gas state.
3. Physical properties of matter can be observed or measured without changing the composition of the matter, such as color, density. Chemical properties involve a change in the composition of matter, like flammability or reactivity.
4. Rust is iron oxide, which is formed by the chemical reaction of iron with oxygen in the air. It is a compound as it is made up of two or more elements (iron and oxygen) chemically combined.
5. Water ($H_2O$), limestone (calcium carbonate $CaCO_3$), and salt (sodium chloride $NaCl$) are compounds made of different elements. Hydrogen ($H_2$) is an element as it consists of only one type of atom.

Answer:

1. b. Period
2. a. solid
3. c. physical;chemical
4. a. A compound
5. d. hydrogen