Chemistry

Question 1

Atomic number

Answer 1

number of protons in an atom

Question 2

Atoms

Answer 2

the particles that make up all materials; the smallest part of an element that can take part in a chemical reaction

Question 3

Electron configuration

Answer 3

arrangement of electrons in electron shells

Question 4

Electron shells

Answer 4

also known as energy levels, the regions surrounding the nucleus where electrons may be found

Question 5

Nucleus

Answer 5

heavy core at the center of the atom, made of protons and neutrons

Question 6

Groups

Answer 6

vertical columns of the periodic table; group number is equal to the number of electrons in the outer shell of atoms of the elements in that group

Question 7

Periodic table

Answer 7

a list of all the known elements, arranged horizontally in order of increasing atomic number and vertically according to the number of electrons in the outer shell

Question 8

Period

Answer 8

horizontal rows of the periodic table; period number of an element is equal to the number of electron shells

Question 9

Ions

Answer 9

‘charged atoms’ ( or a group of atoms) formed by electrons being transferred from one atom to another

Question 10

Aqueous solution

Answer 10

a solution of a substance dissolved in water

Question 11

Formula equation

Answer 11

a chemical equation where the reactants and products are identified by their chemical formulas

Question 12

Law of conservation of mass

Answer 12

the law that states that atoms cannot be created or destroyed during a chemical reaction

Question 13

Product

Answer 13

a substance produced by a chemical reaction

Question 14

Reactant

Answer 14

the initial substance of a chemical reaction

Question 15

Anion

Answer 15

a negatively charged ion

Question 16

Cation

Answer 16

a positively charged ion

Question 17

Combination reaction

Answer 17

a chemical reaction where two reactants combine to form one product

Question 18

Combustion reaction

Answer 18

any chemical reaction where a substance burns in oxygen to produce heat and light

Question 19

Decomposition reaction

Answer 19

a chemical reaction where one reactant breaks apart into two or more products

Question 20

Insoluble

Answer 20

does not dissolve

Question 21

Ion

Answer 21

an atom that has gained or lost electrons to become electrically charged

Question 22

Precipitate

Answer 22

the insoluble product of a precipitation reaction

Question 23

Soluble

Answer 23

able to dissolve

Question 24

Agitation

Answer 24

stirring

Question 25

Catalyst

Answer 25

a chemical that helps to speed up a chemical reaction but is not used up during the reaction

Question 26

Concentration

Answer 26

the amount of a chemical in a certain volume of water

Question 27

Enzyme

Answer 27

a natural occurring catalyst

Question 28

Rate of Reaction

Answer 28

how fast a chemical reaction proceeds.