Atoms and The Periodic Table

Question 1

What are atoms made out of?

Answer 1

Protons, electrons and neutrons.

Question 2

Where is the mass of an atom situated?

Answer 2

In it’s nucleus, which contains protons and neutrons.

Question 3

Which two particles have the same mass?

Answer 3

Neutrons and protons.

Question 4

Are electrons positively or negatively charged?

Answer 4

Negatively charged.

Question 5

What is the mass number?

Answer 5

The total number of protons and neutrons in the nucleus. It is the top number.

Question 6

What is the atomic number?

Answer 6

The number of protons in the nucleus. Meaning it has the same number of electrons. It is the bottom number.

Question 7

What are isotopes?

Answer 7

For any given element, the number of of protons is fixed, but isotopes are when the number of neutrons differ. This changes the mass.

Question 8

What is likely to happen when isotopes have more neutrons than protons?

Answer 8

More likely to decay and can be unstable.

Question 9

What is the relative atomic mass?

Answer 9

The relative atomic mass of an element is the average mass of its atoms, compared to 1/12th the mass of a carbon-12 atom. The relative atomic mass, A r, of an element is calculated from the mass numbers of its isotopes.

Question 10

State the number of electrons allowed in shells 1-4.

Answer 10

Shell 1 has 2 electrons. Shell 2 and 3 both have 8. Shell 4 holds 2 on a standard periodic table.

Question 11

Sodium has an atomic number of 11. Work out the electronic structure of the atom.

Answer 11

There is 11 protons total, so also 11 electrons. Shell 1 will have 2, shell 2 will have 8 (full), shell 3 will have 1. Written as 2,8,1.

Question 12

What are the collumns in the periodic table classes as?

Answer 12

Groups

Question 13

What are the rows in the periodic table classed as?

Answer 13

Periods.

Question 14

What does the group number signify?

Answer 14

The group number indicates the number of electrons in the outer shell. Exception of group 0, who have full shells.

Question 15

What does the period indicate?

Answer 15

The number of occupied electron shells in an atom.

Question 16

What is group 1 of the periodic table?

Answer 16

The alkali metals.

Question 17

What are the alkali metals?

Answer 17

Lithium, sodium, potassium, rubidium, caesium and francium.

Question 18

What are the properties of alkali metals?

Answer 18

They react with oxygen to form oxides.
They react with water to form hydroxides and hydrogen gas.
They react with bromine and chlorine to form bromides and chlorides.

Question 19

Does the reactivity increase or decrease down group 1?

Answer 19

Reactivity increases down the group. Can be dangerous to carry out without safety equipment.

Question 20

What colour do the 3 alkali metals burn when subjected with oxygen?

Answer 20

Lithium burns crimson red.
Sodium burns orange-yellow.
Potassium burns lilac.

Question 21

What are the group 7 elements known as?

Answer 21

The halogens.

Question 22

What are the halogen elements?

Answer 22

Fluorine (toxic) chlorine (reactive) Bromine (both) Iodine (toxic in elemental form) astatine (highly radioactive, no one has even found it because it breaks down too quickly).

Question 23

Does the reactivity increase or decrease when you go down the halogen elements?

Answer 23

Decreases as you go down.

Question 24

What are the group 0 gases also known as?

Answer 24

The noble gases

Question 25

Why are noble gases very unreactive?

Answer 25

They have full outer shells of electrons.

Question 26

Name 3 of the noble gases.

Answer 26

Helium, neon and argon.

Question 27

What is the precipitate for?

Answer 27

Halogen test where halides are identified by a precipitation reaction with silver nitrate.

Question 28

What colours will the precipitates be after adding silver nitrate?

Answer 28

White - the salt was a chloride.
Pale yellow - the salt was a bromide.
Yellow - the salt was an iodide.

Question 29

What happens to chloride, bromide and iodide when subjected to an ammonia solution?

Answer 29

Chlorides dissolve in dilute ammonia solution.
Bromides are insoluble in dilute ammonia but soluble in concentrated ammonia solution.
Iodides are insoluble in both concentrated and dilute ammonia solutions.