WEIGHT AND MASS
PRESSURE
FLUID PRESSURE AND BUOYANCY
CHEMICAL CHANGE
ACIDS, BASES & pH
100
What are the respective units used to measure mass and weight?
mass - kilograms (kg)
weight - newtons (N)
100
What two factors affect the pressure produced between solid objects?
Force and area
100
What three factors affect fluid pressure?
density, gravitational field strength, depth
100
Melting and boiling are examples of what type of change?
physical
100
What pH value is neutral?
7
200
A student has a mass of 50 kg. On Earth, what is their approximate weight?
500 N
200
A person wearing high heels produces more pressure than someone wearing flat shoes. Why?
The smaller area of the heel creates greater pressure.
Area ↓ Pressure ↑
200
Why does water pressure increase with depth?
There is more water above pushing down.
200
What is produced when a metal reacts with oxygen?
A metal oxide
200
What adjective is used to describe a solution with a pH of less than 7?
acidic
300
Give two differences between mass and weight, other than the units they are measured in.
1. mass is the amount of matter, weight is a force acting on the matter
2. mass is the same everywhere, weight can be different on different planets
300
A box pushes down with a force of 200 N. The contact area is 4 m². Calculate the pressure.
50 Pa
300
What is the density of pure water? Ensure you provide the right units.
1000 kg/m3
300
What type of reaction happens when a substance burns in oxygen? (anagram of COMBOS UNIT)
Combustion
300
A solution changes universal indicator from red to green. What has happened to the value of the pH?
It has increased towards neutral.
400
An astronaut has a mass of 100 kg. He travels to the Moon where g = 2 N/kg. What will his mass be on the moon?
100 kg
400
Two blocks have the same weight. Block A has a contact area of 0.5 m² and Block B has an area of 2 m². Which creates more pressure and why?
Block A. It has a smaller area.
400
Which property of an object determines the size of the buoyant force it experiences when it is fully submerged in a fluid?
volume
400
Name two out of five clues that show a chemical reaction has occurred.
A colour change occurs.
A gas is produced (bubbles/fizzing).
A temperature change occurs (heat released or absorbed).
A precipitate (new solid) forms.
Light is produced.
400
What is the name of the ion that forms when acids are dissolved in water? (formula = H3O+)
hydronium ion
500
A 50 kg astronaut travels to a new planet. She discovers that her weight on this planet is 400 N. Calculate the gravitational field strength of the planet. Give units.
8 N/kg
500
A box has a weight of 10 N. It rests on a surface with a contact area of ¼ m × ½ m. Calculate the pressure exerted by the box on the surface.
80 Pa.
500
A football has a weight of 10 N and floats on water. Exactly half of the football is submerged. What is the value of the buoyant force acting on the football?
10 N
500
Hydrochloric acid (HCl) is added to potassium hydroxide (KOH). The reaction is shown below:
HCl + KOH → KCl + H2O
What are the names of the two products formed in this neutralisation reaction?
potassium chloride and water
500
What are the products of acid + alkali?
Salt + water