chemistry 8.1 acids and alkalis 1.3 isotopes 2.3 metals and non-metals

Question 1

what is a neutralisation reaction

Answer 1

when an acid reacts with an alkali to form water and a salt
(acid + alkali —> salt + water).

Question 2

what is the formula to work out relative atomic mass

Answer 2

relative atomic mass = sum of (isotope abundance x isotope mass number) divided by sum of abundances of all the isotopes

Question 3

what is an isotope

Answer 3

an atom with the same number of protons but a different number of neutrons.

Question 4

what is relative atomic mass?

Answer 4

an average mass, taking into account the different masses of isotopes that make up the element and how abundant each isotope is.

Question 5

what happens when an acid neutralises an alkali

Answer 5

water and a salt are produced.

Question 6

what is the colour of an acid in universal indicator

Answer 6

red

Question 7

what is the colour of a neutral solution in universal indicator

Answer 7

green

Question 8

what is the colour of an alkali in universal indicator

Answer 8

purple

Question 9

what is the range of numbers on the pH scale

Answer 9

0-14 where 0 is acidic, 7 is neutral, and 14 is alkaline

Question 10

what is a metal

Answer 10

an element which can form positive ions when it reacts

Question 11

where are most metals found on the periodic table

Answer 11

further down and to the left hand side (the elements in the middle are called transition metals)

Question 12

what are non-metals

Answer 12

elements which don’t form positive ions when they react. they either form negative ions in ionic compounds or bond covalently with other non-metals (excluding hydrogen which forms positive ions)

Question 13

where are non-metals found on the periodic table

Answer 13

the upper right hand side (including Hydrogen)

Question 14

name some physical properties of metals

Answer 14

they’re strong but malleable, they conduct heat and electricity very well, they generally have high melting and boiling points (solid at room temperature)

Question 15

name some physical properties of non-metals

Answer 15

they mostly look quite dull and are more brittle than metals, they generally have lower melting and boiling points (not all are solid at room temperature), they don’t generally electricity and they are often less dense than metals

Question 16

why do metals to the left of the periodic table form positive ions

Answer 16

because they have a smaller amount of electrons in their outer shell, so it is easier for them to lose electrons in order to become more stable (a full outer shell makes an atom more stable)

Question 17

why do non-metals form negative ions

Answer 17

because they have a larger amount of electrons in their outer shell, so it is easier to gain electrons to make the outer shell full to become more stable.

Question 18

what does the group number tell us about an element

Answer 18

how many electrons are in the outer shell and so whether it will form a positive or negative ion

Question 19

what is another name for a positive ion

Answer 19

cation

Question 20

what is another name for a negative ion

Answer 20

anion

Question 21

give a use for a metal

Answer 21

wiring

Question 22

give a use for a non-metal

Answer 22

electronic insulation