CHEM

Question 1

What is an atom?

Answer 1

The smallest part of an element that can exist.

Question 2

What is an element?

Answer 2

A substance made of only one type of atom.

Question 3

Name the three subatomic particles?

Answer 3

Protons, Neutrons and Electrons

Question 4

State the relative masses and charges of the subatomic particles.

Answer 4

Mass: Proton = 1, Neutron = 1, Electron = Negligible. Charge: Protons = +1, Neutron = 0, Electron = -1.

Question 5

What is the plum pudding model?

Answer 5

a ball of positive charge with negative electrons embedded within it.

Question 6

What did the gold foil experiment (alpha particle scattering) prove?

Answer 6

That atoms have a dense nucleus with a positive charge?

Question 7

What did Chadwick discover?

Answer 7

The neutron

Question 8

What did Bohr’s experiment show?

Answer 8

That electrons are in specific shells.

Question 9

What is the atomic number in an atom?

Answer 9

The number of protons in an atom.

Question 10

What is the mass number of an atom?

Answer 10

The number of protons + the number of neutrons

Question 11

In the electron shell model how are the subatomic particles arranged in an atoms?

Answer 11

Protons and neutrons in the nucleus , electrons orbiting in shells.

Question 12

Why is the number of electrons in an atom equal to the number of protons?

Answer 12

As their charges cancel out.

Question 13

How many electrons can go in the first shell?

Answer 13

2

Question 14

How many electrons can go in the second and third shells?

Answer 14

8

Question 15

What are the groups in the periodic table?

Answer 15

The columns numbered 1, 2, 3, 4, 5, 6, 7, 0

Question 16

What can the group tell you about the electrons in an atom?

Answer 16

How many electrons are in the outer shell.

Question 17

What are periods in the periodic table?

Answer 17

The rows

Question 18

What can the group tell you about the electrons in an atom?

Answer 18

How many shells an atom has

Question 19

Why do atoms have no overall charge?

Answer 19

The number protons and neutrons are the equal.

Question 20

What are isotopes?

Answer 20

Atoms of the same element with a different number of neutrons.

Question 21

What is abundance?

Answer 21

The % of atoms in a sample with a particular mass.

Question 22

What is the relative atomic mass of an element?

Answer 22

And average value for the mass that takes account of the abundance of the isotopes of the element.

Question 23

What is relative formula mass?

Answer 23

The sum of relative masses of each atom in a compound.

Question 24

What symbol do we use for relative formula mass?

Answer 24

Mr

Question 25

In the modern periodic table how are the atoms arranged?

Answer 25

By their atomic number and in groups according to their chemical properties.

Question 26

Why did Mendeleev leave gaps in his periodic table?

Answer 26

For elements that had not been discovered yet.

Question 27

Why do elements in the same group have similar properties?

Answer 27

Because they have the same number of electrons in their outer shell.

Question 28

Before the discovery of protons, neutrons and electrons, how did scientists organise the elements?

Answer 28

By atomic weight

Question 29

Which discovery meant that their organising elements by atomic weight was not always correct?

Answer 29

Isotopes

Question 30

Where are the metals on the periodic table always found?

Answer 30

To the left and the bottom of the periodic table.

Question 31

What name is given to elements in group 0?

Answer 31

Noble gases

Question 32

Why are the elements in group 0 so unreactive?

Answer 32

They have full outer shells so do not need to gain or lose electrons.

Question 33

How does the boiling points of group 0 change down the group?

Answer 33

Increases down the group

Question 34

Explain why the group 1 elements are called alkali metals?

Answer 34

They are metals that form alkalis when they react with water.

Question 35

What are the products of the alkali metals in a reaction with with: oxygen, water and halogens?

Answer 35

Oxygen: Metal oxide. Water: Metal hydroxide + hydrogen Halogen: Metal Halide

Question 36

Explain why group 1 elements get more reactive down the group?

Answer 36

More electrons, more shielding , weaker electrostatic from the nucleus to the outer shell, easier to lose and electron.

Question 37

What name is given to elements in group 7?

Answer 37

Halogens

Question 38

How does the boiling point change down the group?

Answer 38

Increases down the group c

Question 39

Explain why group 7 elements get less reactive down the group?

Answer 39

More electrons, more shielding, weaker electrostatic, attraction from the nucleus to the outer shell, easier to lose and electron.

Question 40

What is a displacement reaction?

Answer 40

\where a more reactive element displaces a less reactive one from a compound.

Question 41

Where are the transition metals found in the periodic table?

Answer 41

In the middle

Question 42

Compare the melting point, density, strength, hardness and reactivity of transition metals with group 1 metals.

Answer 42

Higher for all but reactivity.

Question 43

What is distinctive about the ions formed by transition metals?

Answer 43

Can form ions with different charges

Question 44

What is distinctive about compounds formed from transition metals?

Answer 44

They are coloured.

Question 45

What can transition metals be used for?

Answer 45

Catalysts

Question 46

How do you calculate Relative atomic mass?

Answer 46

(% abundance isotope 1 x mass isotope 1) + (% abundance isotope 2 x mass isotope 2) over 100

Question 47

What is relative molecular mass and how so you calculate it?

Answer 47

Relative molecular mass is the mass of a molecule. NH3 becomes 14 + (1x3) = 17. Find the atomic mass of each element and if multiple times the atomic mass by that number.

Question 48

What are the common physical properties of metals?

Answer 48

Solid and Shiny, Conduct electricity and heat, strong, malleable and ductile.

Question 49

What are the common physical properties of non-metals?

Answer 49

Dull, Brittle, Not malleable or ductile, insulating.