Chemistry C1 + C2

Question 1

What charge do protons give to a nucleus?

Answer 1

Positive

Question 2

What charges are electrons?

Answer 2

Negative

Question 3

What is the relationship between protons and electrons?

Answer 3

The amount of protons = the number of electrons

Question 4

What describes at atom?

Answer 4

Its atomic and mass number

Question 5

How are an atomic and mass number determined?

Answer 5

The amount of protons tells you the atomic number

The amount of protons and neutrons combined tells you the masw number

Question 6

What defines an element?

Answer 6

Atoms with the same atomic number

Question 7

How are atoms abbreviated?

Answer 7

Through symbols such as O = oxygen and Na = sodium etc..

Question 8

What are isotopes

Answer 8

Different forms of the same element which have the same number of protons but different number of neutrons .

Question 9

Is relative atomic mass calculated

Answer 9

Sum of (isotope abundance x isotope mass number)
/ sum of abundances of all isotopes

Question 10

Compounds

Answer 10

Atoms that join together to produce a chemically bonded combination of elements

Question 11

How do formulas show what atoms are in a compound?

Answer 11

It shows the combination of element and the reactant that comes from it. For example carbon (C) + oxygen (O) = CO2.

Question 12

How do chemical equations show chemical changes?

Answer 12

They show the change in atoms and what they have formed. For example methane + oxygen = carbon dioxide + water

Question 13

Why do symbol equations need to be balanced and why are they balanced?

Answer 13

They need the same number of atoms on both sides. If the equation is balanced it will make sense as the same atoms have been produced from before - no atoms can be lost or gained.

Question 14

What is the simplest way of seperating substances?

Answer 14

Chromatography

Question 15

How are insoluble solids separated from liquids?

Answer 15

Through filtration

Question 16

What are two ways soluble solids can be separated from solutions?

Answer 16

Evaporation and crystallisation

Question 17

What methods of separation are used to separate rock salt.

Answer 17

Filtration and crystallisation.

Question 18

What separates out two simple solutions?

Answer 18

Simple distillation

Question 19

What is fractional distillation used for?

Answer 19

The mixing of liquids

Question 20

What did Rutherford’s plumb pudding model suggest?

Answer 20

Particles can penetrate through the area surrounding a nucleus but some deflected. When particular atoms strike the nucleus (as it is so concentrated and positively charged.

Question 21

What does the nuclear model suggest?

Answer 21

Electrons form in a cloud around the nucleus of an atom. Surrounding the nucleus in ‘shells’. It states that electrons orbit around these fixed shells.

Question 22

What are the rules of electrons shells?

Answer 22

1) the lowest energy levels are always filled first 2) only a certain number of electrons can fill up each shell - 2,8,8 3) atoms are much happier when there shells are filled 4) if the outer shell is not full then the atom will want to react in order to fill it.

Question 23

How were elements categorised up until recently?

Answer 23

1) their physical and chemical properties and 2) their relative atomic mass.

Question 24

How did Dmitri Mendeleev develop the Periodic table?

Answer 24

He put elements in order of atomic mass with a few exceptions

Question 25

Why were there gaps left in the periodic table?

Answer 25

As there were some elements which were undiscovered, and when they were discovered fitted Mandeleev's theory.

Question 26

What did isotopes suggest about Mandeleev's theory?

Answer 26

That he was correct not to put elements in order of atomic mass but to also take into account their properties.

Question 27

What does the periodic table allow you to do?

Answer 27

It divides metals and non metals and also organises elements inti groups of electrons in the elements outer shell

Question 28

What positive ions do metals form?

Answer 28

Metals

Question 29

What is the difference in physical properties of both metals and non metals

Answer 29

Metals are hard and brittle which conduct heat and electricity, non - metals are the opposite they arent usually solids nor conduct electricity.

Question 30

What type of metals or group 1 elements

Answer 30

Soft reactive metals

Question 31

What metals form with ionic compounds

Answer 31

Alkali metals, group 1 elements form 1+ ions

Question 32

What happens when group 1 metals react with water

Answer 32

The elements produce hydrogen gas

Question 33

What happens when group 1 elements react with chlorine

Answer 33

A salt

Question 34

When group 1 metals react with oxygen what do they produce

Answer 34

Oxides

Question 35

What are halogens

Answer 35

What the group 7 metals are known as halogens which are non metals with coloured vapours

Question 36

What happens to halogens as you go down the group

Answer 36

They become less reactive, have a higher melting and boiling points, and a higher relative atomic mass.

Question 37

How do halogens form molecular compounds

Answer 37

By sharing electrons with other non metals to form a full outer shell.

Question 38

What will happen to less reactive halogens

Answer 38

More reactive halogens will displace them

Question 39

Are group 0s atoms bonded

Answer 39

No

Question 40

Do all elements in group 0 have eight electrons in their outer shell

Answer 40

Yes

Question 41

What happens as you go down the reactivity series of group 0

Answer 41

The boiling points increase, and relative atomic mass increases. The intermolecular forces also become greater due to the increase in boiling point.

Question 42

How are ions formed?

Answer 42

By the transfer of Electrons

Question 43

Which groups are most likely to form ions

Answer 43

Group 1&2 and 6&7 because 1&2 are metals which lose electrons to form positive ions and 6&7 are non metals which gain electrons to form negative ions.

Question 44

What does ionic bonding involve?

Answer 44

The transfer of electrons

Question 45

How do dot and cross diagrams show how ionic compounds are formed

Answer 45

They show the arrangement of electrons in an atom or ion. Each electron is represented by a dot or a cross.

Question 46

What is the composition of a solid like?

Answer 46

Made of strong forces of attraction, fixed together, with closely joined particles

Question 47

What is the composition of a liquid like?

Answer 47

In liquids there is a weak force of attraction between the particles. They are free to move past each other. They also tend to stick closely together. The particles are constantly moving with random motion .

Question 48

What is the composition of gases like?

Answer 48

They have very weak forces of attraction, they are free to move and are far apart. They do not keep a definite shape or volume. There particles move constantly with random motion.

Question 49

How can a solid change state

Answer 49

If it is melted, its forces weaken

Question 50

How does a liquid change state?

Answer 50

Either by freezing it to form a solid or by boiling it to form a gas

Question 51

How does a gas change state?

Answer 51

By condensing it to form a liquid

Question 52

What is relative formula mass?

Answer 52

The relative atomic masses of all atoms in the molecular formula added together

Question 53

How do you calculate the percentage mass of an element in a compound.

Answer 53

Relative atomic mass x number of atoms of that element/ relative formula mass of the compound x 100

Question 54

What is a mole?

Answer 54

A name given to an amount of a substance.

Question 55

How do you find the number of moles in a given mass?

Answer 55

Number of moles = mass in g (of element/compound) / relative formula mass (of an element or compound)

Question 56

What is the conservation of mass?

Answer 56

Where no atoms are destroyed nor created jus conserved

Question 57

How do you find the mass that is conserved?

Answer 57

By adding up the relative formula masses of the substances on each side of the balanced equation

Question 58

Give to ways why the mass will increase in the conservation of mass?

Answer 58

1) its probably because one if the reactants is a gas thats found in the air and all the products are solids, liquids or aqueous. 2) if the mass decreases its because one of the products is a gas and all the reactants are solids, liquids or aqueous.

Question 59

How can you use moles to calculate masses in reactions give an example

Answer 59

In an equation where 1 mole of magnesium and 2 moles of hydrochloric acid react together to form 1 mole of magnesium chloride and 1 mole of hydrogen gas.

Question 60

What are limiting reactants

Answer 60

Limiting reactants are reactions that stop once one reactant is used up

Question 61

What does the amount of product depend on

Answer 61

The limiting reactant

Question 62

What is the concentration of solutions?

Answer 62

The amount of a substance in a certain volume of a solution is called its concentration, the more solute there is in a given volume, the more concentrated the solution.

Question 63

How can concentration be measured?

Answer 63

In g/dm(cubed) - concentration = mass of solute / volume of the solvent.