Topic 1 - What is water?

Question 1

How many hydrogen atoms and how many oxygen atoms are there in one molecule of water?

Answer 1

TWO hydrogen atoms
Are joined to
ONE oxygen atom
To make one molecule of water

Question 2

Which colour is used to represent oxygen atoms?

Answer 2

Chemists use red spheres to represent oxygen atoms.

🔴

Question 3

Which colour is used to represent hydrogen atoms?

Answer 3

Chemists use white spheres to represent hydrogen atoms

⚪️

Question 4

What way are atoms represented?

Answer 4

A way of representing atoms is by using filled (colour) spheres - this is known as a space filling model

Question 5

How do water molecules in a glass of water move?

Answer 5

Water molecules in a glass of water are in constant random movement.

Question 6

What is the chemical formula of water?

Answer 6

H2O

Question 7

What is the chemical symbol of hydrogen?

Answer 7

H

Question 8

What is the chemical symbol oxygen?

Answer 8

O

Question 9

Why is water considered a chemical compound?

Answer 9

Water is a chemical compound because it contains more than one type of atom.

Question 10

Is the water molecule linear (I.e. In a straight line) or bent?

Answer 10

Water molecules are bent; the atoms are not connected in a straight line

Question 11

What is meant by ‘doing science safely’?

Answer 11

Doing science safely means assessing and managing the dangers of harm or damage before embarking on an activity

Question 12

Define the term ‘risk’ in regards to doing science safely?

Answer 12

RISK
The POSSIBILITY that something unpleasant or dangerous may happen.
This consists partly of what happens in the event and the outcome of the activity.
E.g risks related to chemicals individually- risks related to mixing these two chemicals

Question 13

Define the term ‘hazard’ in regards to health and safety?

Answer 13

A hazard is something that could be dangerous or cause or accidents.
It can be an object or situation that poses a level of threat to life, health, property, environment
E.g. Stairs = hazard
Risk = falling

Question 14

What is a ‘risk assessment’?

Answer 14

It is a process in which hazards are identified and the level of risk associated to it. Judgements can then be made as to whether the level of risk is acceptable and if something need to be done to reduce it

Question 15

In the simplest form how can ‘risk’ be rated?

Answer 15

Low
Medium
High

Question 16

What questions does the process of a risk assessment seek to answer?

Answer 16

What can go wrong?

How bad are the consequences?

How often might it happen?

Who might be harmed?

Is there need for action?

Question 17

What safety precautions apply to all practical activities?

4

Answer 17

1) Keep children and animals away while you are working
2) clear your work area of clutter: put all food away and ensure there is nothing for anyone to trip over
3) always wash your hands thoroughly after a practical activity
4) clean thoroughly any household items that you use during your experiment before retiring them to their domestic use

Question 18

Explain the structure of a water molecule?

Answer 18

1 oxygen atom (represented as a red sphere) is joined by 2 hydrogen atoms (represented as 2 white spheres) these are joined to the oxygen atoms by bonds (circular rods)
These combined produce the chemical formula H2o
The structure is not in a straight line it is bent