Atomic Structure and The Periodic Table

Question 1

Atoms have a radius of

Answer 1

0.1 nanometers (1 x 10-10 m)

Question 2

The nucleus of an atom has a radius of

Answer 2

1 x 10-14 metres (1/10000 of the radius of an atom)

Question 3

Atoms charge

Answer 3

Atoms don’t have an overall charge as it has equal protons and electrons

Question 4

Name the region where most of the mass of the atoms is concentrated

Answer 4

The nucleus

Question 5

What is the relative charge of an electron?

Answer 5

-1

Question 6

Name the particles in the nucleus and give their relative charges

Answer 6

Neutrons (0) protons (+1)

Question 7

Mass number

Answer 7

Number on top

Question 8

Atomic number

Answer 8

Bottom number

Question 9

Atoms are the

Answer 9

Smallest part of an element that can exist

Question 10

What are isotopes

Answer 10

Have the same number of protons but a different number of neutrons

Question 11

How to work out the relative atomic mass

Answer 11

Sum of (isotope abundance x isotope mass number)/ 100

Question 12

What is a compound?

Answer 12

Two or more elements chemically combined (in fixed proportions)

Question 13

How to work out the number of atoms in a compound

Answer 13

The sum of All elements involved

Question 14

Name NaCl

Answer 14

Sodium chloride

Question 15

How many atoms in C2H4

Answer 15

6

Question 16

If C2H4 and H2 react to form C2H6, has a new compound been made?

Answer 16

Yes because the atoms in C2H6 are in different proportions to the atoms in the previous

Question 17

What is a reactant

Answer 17

Everything on the left

Question 18

What is a product

Answer 18

Everything on the right

Question 19

Balance Na + Cl = NaCl

Answer 19

2Na + Cl2 = 2NaCl

Question 20

Balance NH2 + O2 = NO + H2O

Answer 20

4NH3 + 5O2 = 4NO + 6H2O

Question 21

What is a mixture

Answer 21

Consists of two or more elements or compounds that aren’t chemically combined together

Question 22

Outline the procedure for setting up a chromatography experiment

Answer 22

1) Draw a line in pencil near the bottom of a piece of chromatography paper.
2) Place a spot of ink on the pencil line. Pour a shallow layer of water or solvent into a beaker. 3) Place the chromatography paper into the container. The water should be below the pencil line and the ink spots.
4) Place a lid in the container and wait for the solvent to rise to the top of the paper.
5) Remove the paper from the container when the solvent had risen close to the top of the paper.

Question 23

Explain the results of a chromatography experiment

Answer 23

Count the spots that the dyes have made and state how many dyes were involved in the specific spots. State which are mixtures. State which dyes contain at least one of the same dyes (no clue what that meant but there you go)

Question 24

What is filtration?

Answer 24

Filtration deprecated insoluble solids from liquids

Question 25

Insoluble

Answer 25

Can’t be dissolved in the liquid

Question 26

Evaporation

Answer 26

Pour the solution into an evaporating dish.
Slowly heat a solution.
Solvent will evaporate.
Solution gets more concentrated.
Crystals will start to form.
Keep heating the evaporating disk until all you have left are dry crystals.

Question 27

Two ways to separate soluble solids from solutions

Answer 27

Evaporation and crystallisation

Question 28

Crystallisation

Answer 28

Pour the solution into an evaporating dish and gently heat the solution.
Some of the solvent will evaporate and the solution will get more concentrated.
Once some of the solvent has evaporated or when you see crystal starter form (the point of crystallisation), remove the dish from the heat and leave the solution to cool.
Salt will form crystals as it becomes insoluble in the cold highly concentrated solution.
Filter the crystals out of the solution and leave them in a warm place to dry.
You could use a drying oven or a desiccator.

Question 29

Why can’t we use evaporation all the time?

Answer 29

You can only use it if the salt doesn’t decompose when it’s heated

Question 30

What can we use to separate rock salt

Answer 30

Filtration or crystallisation

Question 31

What is rock salt?

Answer 31

Rock salt is simply a mixture of salt and sand (grit)

Question 32

Salt and sand are both…

Answer 32

compounds

Question 33

How to separate rock salt

Answer 33

Grind mixture to make salt crystals small so will dissolve easily
Put mixture in water and stir.
Salt dissolves sand won’t
Filter the mixture Salt passes through as if it’s part of the solution and sand gets left on the filter paper
Evaporate the water from the salt so that it forms dry crystals.

Question 34

What is simple distillation?

Answer 34

Simple distillation is used for separate out a liquid from a solution.

Question 35

How to perform simple distillation? (Seawater)

Answer 35

Solution heated. Part of the solution with the lowest boiling point evaporates first.
Vapour cooled, condensed and collected.
The rest of the solution is left behind in the flask.
simple distillation used to get pure water from seawater.
Water evaporates and is condensed and collected.
Only salt left in the flask.

Question 36

What is the problem with simple distillation?

Answer 36

You can only use it to separate things with very different boiling points

Question 37

What is fractional distillation?

Answer 37

If you have a mixture of liquids you can separate it using fractional distillation .

Question 38

How to perform fractional distillation?

Answer 38

Mixture in a flask with a fractional column on top. Then heat.
The different liquids all have different boiling points so they will evaporate at different temperatures.
Liquid with lowest boiling point evaporates first .
When the temperature on the thermometer matches the boiling point of this liquid, it will reach the top of the column.
Liquids with boiling points might also start to evaporate. Column is cooler near the top so liquid will return to the bottom.

Question 39

Who was John Dalton?

Answer 39

At the start of the 19th century, he described atoms as solid spheres, and said that different spheres made up the different elements.

Question 40

Who was J J Thompson?

Answer 40

In 1897, he concluded from his experiments that atoms weren’t solid spheres. His measurements of charge and mass showed that an atom must contain even smaller, negatively charged particles, electrons. The new theory was known as the Plum Pudding Model.

Question 41

What is the Plum Pudding Model?

Answer 41

Showed an atom as a ball of positive charge with negatively charges particles scattered around in it.