Chemsitry Topic 1

Question 1

In what order did each model of the atom come?

Answer 1

1. Solid sphere model
2. Plum pudding model
3. Nuclear model
4. Planetary model

Question 2

What’s the difference between plum pudding and nuclear model of the atom?

Answer 2

1. Plum pudding= no nucleus. Nuclear= small, dense nucleus
2. Plum pudding = electrons are embedded into the positive charge. Nuclear = electrons orbit the nucleus
3. Plum pudding= mass spread out evenly. Nuclear= mass concentrated in nucleus

Question 3

What’s the radius of an atom?

Answer 3

0.1nm (1x10^-10m)

Question 4

What’s the radius of a nucleus?

Answer 4

About 1/10,000 of a atom (1x10^-14)

Question 5

Describe the development of the periodic table according

Answer 5

1. Elements arranged by atomic weight, but patterns didn’t always fit.
2. Arranged elements by atomic weight, left gaps for undiscovered elements, and predicted their properties.
3. New elements were found that matched Mendeleev’s predictions, supporting his table.
4. Elements arranged by atomic number, fixing earlier anomalies.

Question 6

What are the physical properties of metals and non-metals?

Answer 6

Physical properties
Metals: Shiny, good conductors of heat and electricity, malleable and ductile, usually high melting points
Non-metals: Dull, poor conductors, brittle (if solid), usually low melting points

Question 7

What are the chemical properties of metals and non-metals?

Answer 7

Chemical properties
Metals: Lose electrons to form positive ions, react with oxygen to form basic oxides
Non-metals: Gain or share electrons, react with oxygen to form acidic oxides

Question 8

What are group 0 elements called?

Answer 8

Noble gases

Question 9

That happens to noble gases boiling point as you go down the group?

Answer 9

Boiling point increases

Question 10

That are group 1 elements called?

Answer 10

Alkali metals

Question 11

What happens to the reactivity of elements as you gown down group 1?

Answer 11

Reactivity increases

Question 12

What are group 7 elements called?

Answer 12

Halogens

Question 13

What increases in group 7 as you go down the group?

Answer 13

Relative molecular mass, boiling point and melting point

Question 14

What happens to reactivity of halgogens as you go down the group?

Answer 14

Reactivity decreases

Question 15

Compare transition metals with group 1

Answer 15

Group 1- soft, low densities , low mp , very reactive , react quickly with oxygen and halogens, react vigorously with water
Transition metals - high density, high mp, hard , react very little with oxygen and water, each less vigorously with halogens

Question 16

What are the properties of transition metals?

Answer 16

• they have ions of different charge
• form coloured compounds
• useful as catalysts

Question 17

Why is rubidium more reactive than potassium?

Answer 17

The outer shell is further from the nucleus s there is less electrostatic attraction between the nucleus and outer shells so they are lost easier