First Test

Question 1

aqueous solution

Answer 1

the mixture made by adding a soluble substance to water

Question 2

Atom

Answer 2

the smallest part of an element

Question 3

atomic number

Answer 3

the number of protons (which equals the number of electrons) in an atom.

Question 4

balanced symbol equation

Answer 4

a symbol equation in which there are equal numbers of each type of atom on either side of the equation

Question 5

compound

Answer 5

a substance made when two or more elements are chemically bonded together

Question 6

electron

Answer 6

a tiny particle with a negative charge. Electrons orbit the nucleus of atoms or ions in shell

Question 7

electronic structure

Answer 7

a set of numbers to show the arrangement of electrons in their shells (or energy levels)

Question 8

element

Answer 8

a substance made up of only one type of atom. An element cannot be broken down chemically into any simpler substance

Question 9

group

Answer 9

all the elements in the columns (labelled 1 to 7 and 0) in the periodic table

Question 10

ion

Answer 10

a charged particle produced by the loss or gain of electrons

Question 11

isotope

Answer 11

atoms that have the same number of protons but different number of neutrons

Question 12

mass number

Answer 12

the number of protons plus neutrons in the nucleus of an atom

Question 13

neutron

Answer 13

a dense particle found in the nucleus of an atom. It is electrically neutral, carrying no charge

Question 14

noble gases

Answer 14

the very unreactive gases found in Group 0 of the periodic table. Their atoms have very stable electronic structures

Question 15

nucleus (of an atom)

Answer 15

the very small and dense central part of an atom that contains protons and neutrons

Question 16

product

Answer 16

a substance made as a result of a chemical reaction

Question 17

proton

Answer 17

a tiny positive particle found inside the nucleus of an atom

Question 18

reactant

Answer 18

a substance we start with before a chemical reaction takes place

Question 19

shell

Answer 19

an area in an atom, around its nucleus, where electrons are found

Question 20

symbol equation

Answer 20

an equation that helps you see how much of each substance is involved in a chemical reaction by showing the chemical symbols and formulae of all the reactants and products involved