chemistry P1

Question 1

What is an atom?

Answer 1

An atom is the smallest unit of ordinary matter that forms a chemical element.

Question 2

what is the radius of an atom?

Answer 2

0.1 nanometeres (1 × 10 -10 m)

Question 3

what are atoms made up of?

Answer 3

• protons (nucleus)
• neutrons (nucleus)
• electrons (shells)

Question 4

what is the structure of an atom?

Answer 4

• the electrons orbit the nucleus in electron shells.
• the nucleus is in the middle of the atom and it contains protons and neutrons.

Question 5

what is a) the relative mass b) the overall charge of a proton.

Answer 5

a)1 b) +1

Question 6

what is a) the relative mass b) the overall charge of a neutron

Answer 6

a)1 b) 0

Question 7

what is a) the relative mass b) the overall charge of a electron

Answer 7

a)very small b) -1

Question 8

what is an ion?

Answer 8

an atom or group of atoms that has lost or gained electrons

Question 9

atoms are neutral T or F?

Answer 9

True, they have no overall charge.

Question 10

Summary Card: The Nucleus

Answer 10

1) It’s in the middle of the atom
2) It contains protons and neutrons
3) The nucleus radius is about 1/10000 of the radius of an atom
4) The nucleus has a positive charge because of the protons
5) Almost the whole mass of the atom is concentrated in the nucleus

Question 11

Summary Card: Electrons

Answer 11

1) Electrons move around the nucleus in electron shells
2) They are negatively charged, but cover a lot of space.
3) The volume of their orbits determine the size of the atom.
4) Electrons have virtually no mass.

Question 12

what does the atomic number tell you? (bottom number)

Answer 12

The atomic number tells you how many protons there are.

Question 13

What does the mass number tell you?
(top number)

Answer 13

The mass number tells you the total number of protons and neutrons in the atom.

Question 14

How do you calculate the number of neutrons in an atom?

Answer 14

subtract the atomic number from the mass number.

Question 15

What is an element?

Answer 15

An element is a substance made up of atoms that all have the same number of protons in their nucleus.

Question 16

what is a compound?

Answer 16

A compound is a pure substance made from more than one type of element chemically bonded together.

Question 17

How are compounds formed?

Answer 17

compounds are formed when elements react and atoms combine with other atoms.

Question 18

How are elements in the periodic table organised?

Answer 18

By atomic number.

Question 19

what is the radius of an atom?

Answer 19

0.1 nm

Question 20

what is the radius of an atoms nucleus?

Answer 20

1/10,000 of the atom.

Question 21

What is an isotope?

Answer 21

Atoms of the same element with different number of neutrons.

Question 22

What is the relative atomic mass?

Answer 22

The average value of the abundance of isotopes in an element.

Question 23

How do you calculate relative atomic mass?

Answer 23

∑ isotope mass x isotope abundance / 100.

Question 24

What is the maximum number of electrons for shells 1,2 ands 3?

Answer 24

2,8,8.

Question 25

How has the atomic model been developed?

Answer 25

-atoms tiny spheres, unable to divide. -JJ Thompson plum pudding model. (alpha particle scattering) -Niels Bohr; electrons orbit nucleus at fixed distances. - discovery of protons - James Chadwick provided evidence for neutrons in the nucleus.

Question 26

what is a mixture?

Answer 26

to or more substances, not chemically combined.

Question 27

describe the alpha particle scattering experiment.

Answer 27

- beam of alpha particles fired at gold foil -most passed through suggesting mass of atom is concentrated in the centre. - some were deflected proving the nucleus is positively charged -led to the nuclear model.

Question 28

How has the periodic table been developed?

Answer 28

- originally organised by atomic weight (mass number) - Mendeleev changed order of some (reordering some closer to those with similar properties) and left gaps too. - knowledge of isotopes helped to fill in remaining gaps along with Mendeleevs predictions.

Question 29

What does crystallisation separate?

Answer 29

A solid disolved in a liquid.

Question 30

What does filtration separate?

Answer 30

Insoluble solid from solution.

Question 31

What does simple distillation separate?

Answer 31

A liquid from a solution.

Question 32

What does fractional distillation separate?

Answer 32

Mixture of liquids with different boiling points.

Question 33

What are alkali metals?

Answer 33

Metallic elements in group 1. ( one electron in outer shell.)

Question 34

What are properties of alkali metals?

Answer 34

-soft -low density -very reactive

Question 35

What happens as you go down group 1?

Answer 35

The elements become more reactive and denser.

Question 36

What are halogens?

Answer 36

Non-metal elements in group 7.

Question 37

What are properties of halogens?

Answer 37

- react vigorously with metals - very active - molecules consisting with pairs of atoms.

Question 38

What happens as you go down group 7?

Answer 38

Reactivity decreases, boiling and melting point increases.

Question 39

What group are noble gases?

Answer 39

Group 0

Question 40

What are properties of elements in group 0?

Answer 40

-very unreactive - gases at room temperature.

Question 41

Why are noble gases unreactive?

Answer 41

because they have a full outer shell.

Question 42

What happens as you go down group zero?

Answer 42

The boiling point increases.

Question 43

What are properties of transition metals?

Answer 43

- form coloured compounds - can be used as catalysts - Form ions with different charges.

Question 44

How do transition metals compare with group 1 metals.

Answer 44

- harder - denser -higher melting and boiling points - less reactive.

Question 45

Explain covalent bonding.

Answer 45

- two or more metals - atoms share pairs of electrons

Question 46

Explain ionic bonding.

Answer 46

- one or more metal or one or more non metal - particles are oppositely charged ions

Question 47

Explain metallic bonding.

Answer 47

-two or more metals - ions share delocalised electrons.

Question 48

Describe a simple covalent structure and give example;

Answer 48

- few atoms held together by covalent bonds. - typical state is liquids or gases. - intermolecular forces. - low melting/ boiling point. egs. carbon dioxide, water

Question 49

Describe a giant covalent structure and give example;

Answer 49

- giant lattice of atoms - typical state is solids - intramolecular forces - high melting/boiling point egs. diamond, graphite

Question 50

Outline 3 issues with the current particle model.

Answer 50

- doesn't show forces between particles. - spheres are solid - all particles are represented as spherical.

Question 51

What is a property of metals?

Answer 51

High melting/ boiling point

Question 52

What is a property of an alloy?

Answer 52

-hard