Chemical changes and structure

Question 1

atoms are made from

Answer 1

protons, neutrons, and electrons

Question 2

where are the electrons found

Answer 2

in the atoms orbit

Question 3

atoms have an equal number of protons and…

Answer 3

electron

Question 4

what does the atomic number tell us

Answer 4

how many protons an atom has

Question 5

what does the mass number tell us

Answer 5

the total number of protons and electrons

Question 6

what are isotopes

Answer 6

different forms of the same element but with a different number of neutrons

Question 7

what is relative atomic mass

Answer 7

the average mass of an element, taking into account all the isotopes

Question 8

what is valency

Answer 8

the number of electrons an atom of an element uses to combine with others

Question 9

ions are made when…

Answer 9

electrons are transferred

Question 10

how are negative and positive ions formed

Answer 10

positive ions are formed when an atom loses electrons
negative ions are formed when an atom gains electrons

Question 11

how are ionic bonds formed

Answer 11

when a metal and non-metal react together they form a positive and negative ion.
these ions are strongly attracted to eachother, which is called an ionic bond

Question 12

what structure do ionic compounds have

Answer 12

regular lattice

Question 13

why do ionic compounds have high melting and boiling points

Answer 13

because there are strong ionic bonds between the ions

Question 14

what are covalent bonds

Answer 14

where atoms share electrons with each other to have a full outer energy level

Question 15

why are covalent bonds very strong

Answer 15

the positively charged nuclei of the atoms are attracted to the shared electrons

Question 16

what are diatomic molecules

Answer 16

covalent molecules containing only two atoms

Question 17

what are the diatomic elements

Answer 17

H2, N2, O2, F2, Cl2, Br2, I2
Have No Fear Of Ice CoLd BeeR

Question 18

why are the melting and boiling points of covalent molecular substances low

Answer 18

because the forces of attraction between the molecules are weak

Question 19

what determines the shape of covalent molecular substances

Answer 19

the number and direction of bonds around the central atom

Question 20

what is the gram formula mass

Answer 20

the average masses of all the atoms or ions in a compound added together

Question 21

what is a base

Answer 21

substance that neutralises an acid

Question 22

what solution can be made by dissolving a soluble base in water

Answer 22

an alkaline solution

Question 23

what solution can be made by dissolving a soluble non-metal oxide in water

Answer 23

an acidic solution

Question 24

what ions do acids form in water

Answer 24

H+ ions

Question 25

what ions do alkalis form when dissolved in water

Answer 25

OH- ions

Question 26

what products are produced when an acid and a base react together

Answer 26

salt + water

Question 27

what are the most common salts and acids

Answer 27

hydrochloric acid, sulfuric acid, nitric acid. chloride salt, sulfate salt, nitrate salt

Question 28

what products are produced when an acid, metal oxide or hydroxide react together

Answer 28

salt + water

Question 29

what are spectator ions

Answer 29

ions that remain unchanged after the reaction

Question 30

what are titrations used for

Answer 30

to analyse the concentration of solutions. titrations tell us exactly how much of an acid is needed to neutralise an alkali/ vice versa

Question 31

what pH value would a neutral solution have

Answer 31

7

Question 32

describe the relationship between the concentration of H+ ions and pH

Answer 32

the higher the concentration of H+ ions a compound has, the more acidic it is

Question 33

what is the rate of a chemical reaction measuring

Answer 33

how frequently particles collide

Question 34

what are the four factors that affect the rate of reaction

Answer 34

temperature, concentration, surface area, and the presence of a catalyst

Question 35

why does temperature affect the rate of a reaction

Answer 35

because an increase in temperature is an increase in particle speed, causing collisions to happen more frequently

Question 36

the rate of a reaction can be measured in different ways, such as...

Answer 36

change in mass, volume of gas given off or precipitation and colour change