Lo2 PT 2

Question 1

How many elements are there

Answer 1

92

Question 2

Who made the periodic table

Answer 2

Dimitri Mendeleev

Question 3

What are groups

Answer 3

Vertical columns, elements in the same group have similar chemical properties

Question 4

What are periods

Answer 4

Horizontal rows that show the size of the atom

Question 5

Where are metals found

Answer 5

On the left of the periodic table

Question 6

Where are non-metals found

Answer 6

On the right of the periodic table

Question 7

What’s in group 1

Answer 7

Alkali metals

Question 8

What’s in group 2

Answer 8

Alkaline earth metals

Question 9

What’s the block of metals in the middle of the periodic table called

Answer 9

Transition metal block

Question 10

What’s group 7 called

Answer 10

Halogens

Question 11

What’s group 8/0 called

Answer 11

Noble gases

Question 12

Properties of metals

Answer 12

Shiny when polished or freshly cut, good conductors of heat and electricity, malleable and flexible, ductile, solid at room temperature (except for mercury (hg) ) and sonorous

Question 13

Properties of non-metals

Answer 13

Dull, insulators, brittle, non-ductile, solids liquids and gases at room temperature, make a dull thud when hit

Question 14

Where do some of the symbols of elements come from

Answer 14

Their Latin or greek names

Question 15

Steps in scientific method

Answer 15

Observation -> question -> hypothesis -> experimentation -> analysis -> conclusion

Question 16

An atom has 3 subatomic particles, these are

Answer 16

Neutrons that don’t have a charge, protons that have a positive charge and electrons that have a negative charge

Question 17

Properties of proton

Answer 17

Mass: 1
Charge: +
Symbol: p+
Position in atom: centre/nucleus

Question 18

Properties of neutron

Answer 18

Mass: 1
Charge: 0
Symbol: n°
Position: centre/nucleus

Question 19

Properties of electron

Answer 19

Mass: almost 0
Charge: -
Symbol: e-
Position in atom: in shells

Question 20

Mass is not in g/kg it is in

Answer 20

AMU (Atomic mass unit)

Question 21

Atoms are always neutral because

Answer 21

They have the same number of protons and electrons

Question 22

Where is the atomic number and what does it show

Answer 22

It is above the symbol of the element and it shows the total amount of neutrons and protons in the nucleus

Question 23

Where is the mass number and what does it show

Answer 23

It is below the symbol of the element and it tells us how many protons are in the nucleus

Question 24

the mass number (larger number) is equal to

Answer 24

the number of protons and neutrons of the element

Question 25

The atomic number (small number) is equal to

Answer 25

the number of protons

Question 26

how do you find the number of neutrons

Answer 26

mass number (larger number) - atomic number (smaller number)

Question 27

how many electrons can the first three shells take up

Answer 27

1st shell= 2 electrons 2nd shell= 8 electrons 3rd shell= 18 electrons

Question 28

what is the 2(n)² rule

Answer 28

it is how to find how many electrons a number of shells can hold (n = shell number)

Question 29

what does a group number tell you

Answer 29

how many electrons the atom has in its outer shell

Question 30

what does the period number tell you

Answer 30

how many shells the atom has in general

Question 31

every type of atom has a mass, why don't we usually measure it

Answer 31

because it is usually too small to measure

Question 32

what element did scientists choose to be the standard form

Answer 32

carbon because its AMU is 12

Question 33

how is a mass of an atom found

Answer 33

by comparing it to the carbon atom

Question 34

what is this term called

Answer 34

relative atomic mass (AMU)

Question 35

What are isotopes

Answer 35

isotopes are atoms of the same element which have a different number of neutrons but the same amount of protons and electrons

Question 36

the atomic number remains the same but the mass number changes for the different isotopes why?

Answer 36

because the protons stay the same but its the neutrons changing, therefore the mass number changes and the atomic number remains the same since the atomic number is just the protons which don't change and the mass number is a mix of protons and neutrons.

Question 37

how to get the RAM

Answer 37

you first take both isotopes and there abundance and times them together (example= cl- 35= 35 x 37% = 2625 cl- 37= 37 x 25% = 925) then add the answers (2625 + 925) finally divide that answer by 100 (3500/100 = 35.5)

Question 38

what is RAM

Answer 38

RAM is the average of all the mass numbers of the isotope

Question 39

what is Mass number

Answer 39

it is the number of protons and neutrons in the nucleus of the atom

Question 40

list some useful isotopes

Answer 40

I- 131= used in radiotherapy I- 125= used to treat brain cancer Co- 60= sterilisation of medical equipment

Question 41

some examples of radioactive isotopes

Answer 41

Uranium-235, Plutonium-240, Radium-226, Radium-228

Question 42

Explain why some isotopes are radioactive

Answer 42

Some isotopes are radioactive because there is an imbalance between the number of protons and neutrons in the nucleus therefore their atomic nuclei are unstable.