Atomic Structure / Periodic Table (1)

Question 1

What were John Daltons ideas about atoms in 1803

Answer 1

He thought that all matter was made of tiny particles called atoms, which he imagined as tiny spheres that could not be divided.

Question 2

What were J J Thomson ideas about atoms in 1900s

Answer 2

carried out experiments and discovered the electron. This led him to suggest the plum pudding model of the atom. In this model, the atom is a ball of positive charge with negative electrons embedded in it - like currants in a Christmas pudding.

Question 3

In 1909 what did Ernest Rutherford discover

Answer 3

• designed an experiment to test the plum pudding model. In the experiment, positively charged alpha particles were fired at thin gold foil. Most alpha particles went straight through the foil. But a few were scattered in different directions.
• This evidence led Rutherford to suggest a new model for the atom, called the nuclear model. In the nuclear model:
• the mass of an atom is concentrated at its centre, the nucleus
• the nucleus is positively charged

Question 4

what did James Chadwick discover in 1932

Answer 4

• found evidence for the existence of particles in the nucleus with mass but no charge. These particles are called neutrons. This led to another development of the atomic model, which is still used today.

Question 5

What is Atomic Number

Answer 5

The number of protons in an atom

Question 6

What is mass number

Answer 6

• Number of protons + Neutrons

Question 7

What is an isotope

Answer 7

Atoms of the same element with different numbers of neutrons

Question 8

How do you calculate relative atomic mass

Answer 8

Total mass of Atoms / Total number of Atoms

Question 9

How did Dmitri Mendeleev organise the elements

Answer 9

• he arranged the elements in order of increasing atomic weights.
• He also took into account the properties of the elements and their compounds.

Question 10

What are metals

Answer 10

• Elements which can form positive ions when they react

- generally react to form a full outer shell

Question 11

What are the characteristics of metals

Answer 11

• They’re strong, but can be bent or hammered into different shapes (malleable)
• Very good conductors of eat and electricity
• high boiling and melting points

Question 12

What are the characteristics of transition metals

Answer 12

• they have more than one ion
• often coloured
• often make good catalysts

Question 13

What are the trends for group 1 metals

Answer 13

• Increasing reactivity
• lower melting and boiling points
• higher relative atomic mass

Question 14

What are the characteristic of group 1 metals

Answer 14

• are soft (they can be cut with a knife)
• have relatively low melting points
• have low densities

Question 15

How does Lithium react with Water

Answer 15

Fizzes steadily; slowly becomes smaller until it disappears

Question 16

How does Sodium react with Water

Answer 16

Fizzes rapidly; melts to form a ball; quickly becomes smaller until it disappears

Question 17

How does Potassium react with Water

Answer 17

Burns violently with sparks and a lilac flame; quickly melts to form a ball; disappears rapidly, often with a small explosion

Question 18

What are the trends for group 7 metals

Answer 18

• the atoms become larger
• the outer electron becomes further from the nucleus
• the force of attraction between the nucleus and

the outer electron decreases
the outer electron is lost more easily

Question 19

What is Chlorine

Answer 19

A pale green gas

Question 20

what is bromine

Answer 20

a brown liquid

Question 21

what is iodine

Answer 21

A purple/black solid

Question 22

What are the characteristics of group 0 elements

Answer 22

• they are called noble gases
• they have a full outer shell so they are very unreactive
• they are all colourless gases at room temp
• as they are inert they’re non flammable

Question 23

What are the patterns in the noble gases

Answer 23

• The boiling points increase as you move down