Topic 1 - Atom & Equations

Question 1

Element

Answer 1

Only made up of one type of atom (it could be individual atoms, pairs or groups, but there is only one type)

Question 2

compound

Answer 2

Made up of more than one type of atom (chemically joined); but each molecule/particle is the same

Question 3

Mixture

Answer 3

Made of different elements and/or compounds, but they ARE NOT chemically joined

Question 4

Radius of an atom

Answer 4

1 x 10 (-10)

Question 5

Radius of a nucleus (of an atom)

Answer 5

1 x 10 (-14)

Question 6

What is the smallest part of an element?

Answer 6

An atom (still has the properties of that element)

Question 7

Relative mass (of subatomic particles)

Answer 7

Electron - 0.0005
Proton - 1
Neutron - 1

Question 8

Charge of subatomic particles

Answer 8

Electron -} -1
Proton -} +1
Neutron -} 0

Question 9

Position of subatomic particles

Answer 9

Electron -} orbiting outside
Proton-} nucleus
Neutron -} nucleus

Question 10

Atomic number

Answer 10

Number of protons/electrons (if the the atom is neutral)

Question 11

how do you calculate the number of neutrons (in the periodic table)

Answer 11

mass number - atomic number

Question 12

Isotopes

Answer 12

Atoms of the same elements with the same number of protons but a different number of neutrons (same atomic number, but a different mass number)

Question 13

John Dalton

Answer 13

Discovered the solid sphere model (in 1803)

Question 14

J.J. Thomson

Answer 14

Discovered the plum-pudding model in 1904

Question 15

Plum-pudding model

Answer 15

atom composed of electrons scattered throughout a spherical count of positive charge

Question 16

Ernest Rutherford

Answer 16

Discovered the nuclear model in 1911

Question 17

Niels Bohr

Answer 17

Discoverer of the planetary model in 1913

Question 18

Erwin Schrodinger

Answer 18

Discoverer of the Quantum model in 1926

Question 19

Rutherford’s Alpha particles scattering experiment

Answer 19

He fired positively-charged alpha particles at a thin sheet of gold

Question 20

What would happen if Thomson’s model was correct (particles scattering experiment)

Answer 20

If his model was correct, all of the alpha particles would go straight through the spread-out positive charge

Question 21

What actually happened during the particles scattering experiment?

Answer 21

Most went straight through, but a few bounced back.
- Led Rutherford to suggest in 1911 that all of the positive charge is concentrated at the centre in the nucleus
- The atom then thought to be electrons orbiting a nucleus made of protons. Most of the atom is empty space

Question 22

Dalton - Development & Problem

Answer 22

Development - Discovered many elements (first person to give elements symbols). Worked out that atoms have different atomic weights

Problem - no problem

Question 23

Dobereiner - Development & Problem

Answer 23

Development - Made 3 triads of elements with similar properties

Problems - Couldn’t find any other triads with the elements known at the time

Question 24

Newlands - Development & Problem

Answer 24

Development - Put the elements in order of atomic weight (noticed that every 8th element had similar properties)

Problem - He couldn’t make the pattern fit for all known elements after calcium. He also put 2 elements in the same place.

Question 25

Mendeleev - Development & Problem

Answer 25

Development - built on Newlands work and placed elements in atomic weight but left gaps to keep elements with similar properties in the same group

Problem - Needed to swap the order of elements in order to keep elements with similar properties in the same group

Question 26

Modern Day periodic table

Answer 26

Elements are now in order of atomic number rather than weight which resolved Newlands problem.