Unit 2 List 1 Chemistry

Question 1

Atoms

Answer 1

the basic building block of chemistry.

Question 2

Molecules

Answer 2

a group of atoms bonded together, representing the smallest fundamental unit of a chemical compound that can take part in a chemical reaction.

Question 3

Substance

Answer 3

a pure form of matter.

Question 4

Homogenous Mixtures

Answer 4

contains two or more substances that are evenly distributed with each other.

Question 5

Heterogenous Mixture

Answer 5

a mixture in which the composition is not uniform throughout the mixture

Question 6

Chemical properties

Answer 6

a property of a substance that is observed when a substance undergoes a chemical change.

Question 7

Physical properties

Answer 7

a characteristic of a substance that can be observed or measured without changing the identity of the substance.

Question 8

Isotopes

Answer 8

Atoms with the same number of protons but different numbers of neutrons

Question 9

Elements

Answer 9

a chemical substance whose atoms all have the same number of protons.

Question 10

Compounds

Answer 10

A chemical compound is a chemical substance composed of many identical molecules containing atoms from more than one chemical element held together by chemical bonds.

Question 11

reactants

Answer 11

In chemistry, a reagent or analytical reagent is a substance or compound added to a system to cause a chemical reaction, or test if one occurs.

Question 12

products

Answer 12

the substances that are created when two or more substances react in a chemical reaction.

Question 13

hydrogen bonds

Answer 13

a special type of dipole-dipole attraction between molecules, not a covalent bond to a hydrogen atom

Question 14

covalent bonds

Answer 14

a chemical bond that involves the sharing of electrons to form electron pairs between atoms.

Question 15

Ionic bonds

Answer 15

result from the attraction between oppositely charged ions.

Question 16

cation

Answer 16

a positively charged ion, i.e. one that would be attracted to the cathode in electrolysis.

Question 17

anion

Answer 17

a negatively charged ion, i.e. one that would be attracted to the anode in electrolysis.

Question 18

periodic table groups

Answer 18

Groups are numbered 1–18 from left to right.

Question 19

periodic table rows

Answer 19

seven horizontal rows, called periods or series

Question 20

valence electrons

Answer 20

the electrons in the outermost shell, or energy level, of an atom.

Question 21

PH scale

Answer 21

measures how acidic or alkaline a substance is.

Question 22

Acids

Answer 22

A chemical that gives off hydrogen ions in water and forms salts by combining with certain metals

Question 23

Bases

Answer 23

the bottom support of anything; that on which a thing stands or rests