definitions

Question 1

atom

Answer 1

The smallest unit of a substance that can exist

Question 2

nucleus

Answer 2

The central part of an atom containing the protons and neutrons

Question 3

proton

Answer 3

A positive particle within the nucleus of an atom

Question 4

neutron

Answer 4

A neutral particle within the nucleus of an atom

Question 5

electron

Answer 5

A very tiny negative particle that exists in shells around the nucleus of an atom

Question 6

atomic number

Answer 6

The number of positive protons in the nucleus of an atom

Question 7

mass number

Answer 7

The total number of protons and neutrons within the nucleus of an atom

Question 8

Bohr model

Answer 8

A model of an atom showing a small nucleus (positively charged) surrounded by negative electrons moving around the nucleus in orbits.

Question 9

periodic table

Answer 9

A table of the chemical elements arranged in order of atomic number so that elements with similar atomic structure appear in vertical columns.

Question 10

period

Answer 10

a horizontal row in the periodic table

Question 11

group

Answer 11

a vertical row in the periodic table

Question 12

electron shell

Answer 12

Regions around a nucleus that contain a specific number of electrons

Question 13

electron configuration

Answer 13

The specific arrangement of electrons in shells around the nucleus

Question 14

valance electron

Answer 14

Electrons in the outermost shell of an atom

Question 15

ion

Answer 15

An atom that has lost electrons or gained electrons and is no longer neutral

Question 16

polyatomic ion

Answer 16

Ions that contain more than one type of atom

Question 17

transition metal

Answer 17

The elements in the middle section of the periodic table. Transition metal ions can exhibit more than one charge

Question 18

compound

Answer 18

Two or more elements joined together through a chemical bond

Question 19

element

Answer 19

Consists of ONLY one type of atom

Question 20

ionic compound

Answer 20

The attraction between a positive ion and a negative ion

Question 21

covalent compound

Answer 21

Two or more elements bonded together through the sharing of electron pairs

Question 22

reactant

Answer 22

The starting substances in a chemical reaction

Question 23

product

Answer 23

The finishing substances in a chemical reaction

Question 24

chemical reaction

Answer 24

The re arrangement of atoms to form new substances

Question 25

combustion

Answer 25

A chemical reaction where a substance is combined with oxygen and energy is released

Question 26

synthesis reaction

Answer 26

A reaction where simple elements or compounds combine to form a more complex compound

Question 27

decomposition reaction

Answer 27

A reaction where a more complex compound splits into simpler elements or compounds

Question 28

displacement reaction

Answer 28

A reaction where a more reactive element “pushes out” a less reactive elements from a compound and takes its place

Question 29

pop test

Answer 29

A test for hydrogen gas, a popping sound is heard when the gas is hydrogen

Question 30

limewater

Answer 30

A test for carbon dioxide gas, colourless limewater turns cloudy when the gas is carbon dioxide

Question 31

splint test

Answer 31

A test for oxygen gas, the splint glows brightly when the gas is oxygen

Question 32

soluble

Answer 32

A substance that dissolves in water forming a transparent solution

Question 33

insoluble

Answer 33

A substance that does not dissolve in water

Question 34

precipitation reaction

Answer 34

A reaction between two transparent solution where one of the products is not soluble in water

Question 35

endothermic

Answer 35

A reaction that released energy to the surroundings

Question 36

exothermic

Answer 36

A reaction that absorbs energy from the surroundings