Atomic structure and The Periodic Table

Question 1

What is the relative atomic mass?

Answer 1

Is an average mass taking into account all the masses of all the isotopes that make up the element

Question 2

How do you calculate the Relative Atomic Mass, given isotope abundance?

Answer 2

Sum of isotope abundance * mass/ sum of all abundances of all isotopes.

The abundance number is the percentage. You times the mass by it. The mass is the isotope described in the question

Question 3

What is ionic bonding?

Answer 3

Where an element GIVES or RECEIVES an electron to gain a full outer shell and form either a positive or negative ion. It is formed when a metal and non-metal bond.
eg. Na + Cl, Na gives it’s one outer shell electron to Cl to gain an outer shell forming a positive ion and chlorine forms a negative ion

Question 4

What is covalent bonding?

Answer 4

Where a 2 or more non-metals SHARE electrons to gain full outer shells and form negative ions. Eg Hydrogen shares it’s electron with chlorine to gain full outer shells

Question 5

What is a mixture?

Answer 5

2 or more elements or compounds mixed together

Question 6

What is more easy to seperate? Mixtures or compounds?

Answer 6

Mixtures

Question 7

How would you carry out paper chromatography?

Answer 7

Draw a line at the bottom of the sheet of filter paper with a paper as they are insoluble.
Add a spot of ink to the line and place the sheet in a beaker of solvent, for example water
Make sure the ink isn’t touching the solvent as it will dissolve.
place a lid on the beaker to stop it evaporating.
The solvent should seep up the paper carrying the ink with it.
the different dyes will go up the paper at different rates and you can see them separated. If any are insoluble they won’t leave the pencil line.
When the solvent as reached by the top of the paper take it out to dry.
The end result are different coloured dots, this is called a chromatogram.

Question 8

What is the point of chromatography?

Answer 8

To separate mixtures like ink or dyes

Question 9

What are methods of separating mixtures?

Answer 9

Chromatography
Filtration and Crystallization.
Evaporation.

Question 10

When would you carry out filtration?

Answer 10

If the mixture is insoluble

Question 11

What methods could you use to separate soluble solids from solutions?

Answer 11

Evaporation and Crystalization

Question 12

How do you carry out evaporation?

Answer 12

Pour the solution into an evaporating dish
Slowly heat the solution. The solvent will evaporate slowly and crystals with begin to form as the solution gets more concentrated.
Keep heating until you’re left with dry crystals only.

Question 13

How do you carry out crystallization?

Answer 13

Pour the solution into an evaporating dish
Slowly heat the solution. The solvent will evaporate slowly and crystals with begin to form as the solution gets more concentrated.
Remove the dish and leave it to cool. They will form crystals slowly and should be left to dry in a warm spot.

Question 14

What is the use of distillation?

Answer 14

It is to separate out solutions.

Question 15

What is the use of fractional distillation?

Answer 15

To separate different liquids like crude oil.

Question 16

What are properties of Transition elements?

Answer 16

They're good conductors of heat and electricity
Dense, strong and shiny.
They can have more than one ion.
Coloured metal ions.
Make as good catalysts.

Question 17

What is the equation where a metal reacts with water every time.

Answer 17

Metal + Water –> Metal Hydroxide + Hydrogen

Question 18

What is the equation for a reaction between a metal and chlorine?

Answer 18

Metal + Chlorine –> Metal Chloride

Form white metal chloride salts.

Question 19

What happens with group 1 elements when they react with oxygen?

Answer 19

They form oxides
LI2O
NA2O
K2O2

Question 20

For each of the halogens:
state the order they go in
What colour they are
what state they come as

Answer 20

Fluorine- poisonous YELLOW GAS
Chlorine- GREEN GAS
Bromine- RED LIQUID
Iodine- PURPLE GAS or GREY SOLID

Question 21

Why do the halogens get less reactive as you go down the group?

Answer 21

The electrons are further away from the nucleus so can’t form as easily

Question 22

How do the boiling points change as you go down group 0?

Answer 22

Their boiling points increase, due to the increase in electrons meaning the greater the intermolecular forces between them

Question 23

What are the negatives about dot and cross diagrams?

Answer 23

They don’t show the structure of the ion, the size of the ions and how they’re arranged.

Question 24

What do giant ionic compounds do when placed into water?

Answer 24

They dissolve easily, allowing them to conduct electricity.

Question 25

How do you find the empirical formula?

Answer 25

Count the dot and cross diagrams, see how many of each atom there is, work out the charges they would form, work out how many there would need to be to form a neutral charge.

Question 26

What make covalent bonds so strong?

Answer 26

The electrostatic forces between them

Question 27

What don’t covalent bonds show?

Answer 27

How the atoms are arranged and the relative sizes of the atoms.

Question 28

Give 2 examples of simple molecular substances.

Answer 28

Any from:
Oxygen
Chlorine
Nitrogen
Hydrogen
HCL