F4 DEFINITIONS

Question 1

Matter

Answer 1

something that has mass and occupies space

Question 2

Atom

Answer 2

the smallest particle of an element that can take part in a chemical reaction

Question 3

Proton number

Answer 3

The number of protons in the nucleus of an atom

Question 4

Nucleon number

Answer 4

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

Question 5

Isotope

Answer 5

atoms of the same element with the same proton number but different number of neutrons

Question 6

Natural abundance

Answer 6

the percentage of isotopes present in a natural sample of element

Question 7

Valence electrons

Answer 7

electrons in the outermost shell of an atom

Question 8

Relative atomic mass

Answer 8

the average mass of an atom of the element compared to 1/12 of the mass of one carbon-12 atom

Question 9

Relative molecular mass

Answer 9

the average mass of the molecule compared to 1/12 of the mass of one carbon-12 atom

Question 10

Relative formula mass

Answer 10

relative mass of an ionic substance

Question 11

Molar mass

Answer 11

the mass of one molecule of a substance

Question 12

Molar volume

Answer 12

the volume occupied by 1 mole of a gas which is 24 dm^3 at room conditions and 22.4 dm^3 at standard temperature and pressure

Question 13

Chemical formula

Answer 13

representation of a chemical substance using alphabets to represent the atoms and subscript numbers to show the number of each type of atom found in the elementary entities of the substance

Question 14

Empirical formula

Answer 14

chemical formula that shows the simplest ratio of the number of atoms of each element in a compound

Question 15

Molecular formula

Answer 15

chemical formula that shows the actual number of the atoms of each element found in a molecule of a compound

Question 16

Group

Answer 16

vertical column in the periodic table of elements

Question 17

Period

Answer 17

horizontal row in the periodic table of elements

Question 18

Chemical bond

Answer 18

formed when electron transfer or electron sharing takes place

Question 19

Ionic bond

Answer 19

transfer of electrons between a metal atom and a non-metal atom

Question 20

Covalent bond

Answer 20

non-metal share their electrons to achieve stable duplet or octet electron arrangement

Question 21

Hydrogen bond

Answer 21

attraction forces between hydrogen atom, H that has bonded with an atom of high electronegativity, such as N, O or F in another molecule

Question 22

Dative bond (coordinate bond)

Answer 22

type of covalent bond where the electron pair that is shared comes from one atom only

Question 23

Delocalised electron

Answer 23

Electrons that move freely and is not owned by any atom nor ion

Question 24

Metallic bonding

Answer 24

electrostatic attraction force between sea of electron & positively-charged metal ions

Question 25

Acid

Answer 25

chemical substance that ionises in water to produce hydrogen ions

Question 26

Alkali

Answer 26

chemical substance that ionises in water to produce hydroxide ions (base that is soluble in water)

Question 27

Base

Answer 27

chemical substance that reacts with acid to produce salt and water only

Question 28

Base consists of what type of metal

Answer 28

metal oxide and metal hydroxide

Question 29

pH

Answer 29

logarithmic measure of concentration of hydrogen ions in an aqueous solution

Question 30

strong/weak acid/alkali

Answer 30

acid/alkali that ionises completely/partially in water to produce hydrogen/hydroxide ions

Question 31

concentration

Answer 31

mass of solute dissolved in 1 dm^3 solution

Question 32

molarity

Answer 32

number of moles of solute dissolved in 1 dm^3 solution

Question 33

standard solution

Answer 33

solution with known concentration

Question 34

neutralisation

Answer 34

reaction between acid and alkali to produce salt and water only

Question 35

end point

Answer 35

point in titration at which the acid-base indicator changes colour

Question 36

salt

Answer 36

ionic compound formed when the hydrogen ions from acid is replaced when the metal ion on ammonium ion

Question 37

rate of reaction

Answer 37

changes in quantity of reactant or product per unit time

Question 38

alloy

Answer 38

mixture of two or more elements where the main element is a metal

Question 39

composite material

Answer 39

solid material made from combining two or more non-homogenous substances, that is a matrix substance and a strengthening substance