Unit 1 Atom Elements And Compounds

Question 1

insoluble

Answer 1

Unable to dissolve in a particular solvent. For example, sand is insoluble in water.

Question 2

atom

Answer 2

The smallest part of an element that can exist.

Question 3

balanced chemical equation

Answer 3

A chemical equation is a equation using chemical formulas, so that the number of units of each element present is the same on both sides of the arrow.

Question 4

compound

Answer 4

A substance formed by the chemical union of two or more elements.

Question 5

conservation of mass

Answer 5

The law of conservation of mass states that mater cannot be created or destroyed in a chemical reaction

Question 6

electron

Answer 6

Subatomic particle, with a negative charge and a negligible mass relative to protons and neutrons.

Question 7

element

Answer 7

A substance made of one type of atom only.

Question 8

formula

Answer 8

A combination of symbols that indicates the chemical composition of a substance.

Question 9

ion

Answer 9

Electrically charged particle, formed when an atom or molecule gains or loses electrons.

Question 10

ionic compound

Answer 10

An ionic compound occurs when a negative ion joins with a positive ion.

Question 11

ionic equation

Answer 11

A chemical equation that shows how positively charged ions join with negatively charged ions to make a compound

Question 12

mass

Answer 12

The amount of matter an object contains. Mass is measured in kilograms (kg) or grams (g).

Question 13

molecule

Answer 13

A collection of two or more atoms held together by chemical bonds.

Question 14

precipitate

Answer 14

A suspension of particles in a liquid formed when a dissolved substance reacts to form an insoluble substance, eg in a precipitation reaction.

Question 15

precipitation reaction

Answer 15

A reaction in which an insoluble solid is formed when certain solutions are mixed.

Question 16

product

Answer 16

A substance formed in a chemical reaction.

Question 17

reactant

Answer 17

A substance that reacts together with another substance to form products during a chemical reaction.

Question 18

soluble

Answer 18

Able to dissolve in solvent. For example, sugar is soluble in water because it dissolves to form sugar solution.

Question 19

state symbol

Answer 19

A symbol used in chemical equations to show if a substance is a solid, a liquid, a gas, or an aqueous solution.

Question 20

subscript

Answer 20

A letter or number written below the line.

Question 21

superscript

Answer 21

A character (number, letter or symbol) that appears slightly above the normal line of type, and that is usually smaller than the rest of the text.

Question 22

word equation

Answer 22

An equation in which only the names of the reactants and products are used to model a reaction.

Question 23

Aqueous

Answer 23

Dissolved in water to form a solution.

Question 24

charge

Answer 24

Electrical charge can be positive or negative. Like charges (+ and + or - and -) repel but unlike charges (+ and -) attract each other.

Question 25

covalent bond

Answer 25

A bond between atoms formed when atoms share electrons to achieve a full outer shell of electrons.

Question 26

covalent compound

Answer 26

Compounds, commonly formed between non-metal elements, by sharing electrons between atoms to form covalent bonds. All molecular compounds are covalent.

Question 27

insoluble

Answer 27

Unable to dissolve in a particular solvent. For example, sand is insoluble in water.

Question 28

metal

Answer 28

Shiny element that is a good conductor of electricity and heat, and which forms basic oxides.

Question 29

non-metal

Answer 29

Element that is a poor conductor of electricity and heat, and which forms acidic oxides.

Question 30

particle

Answer 30

A general term for a small piece of matter. For example, protons, neutrons, electrons, atoms, ions or molecules.

Question 31

Spectator ion

Answer 31

An ion that is exactly the same on both sides of an ionic equation.