How many bones does a skeleton have?
206
(270 for babies)
What is friction?
A force that slows down a moving object.
What are 3 properties of metals?
1. Good conductors of electricity
2. Ductile (can be drawn into wires)
3. Malleable (can be bend into different shapes)
What are the 2 main factors that cause a rock to change?
Heat and pressure.
Name 4 components of blood
1. White blood cells (fight germs)
2. Red blood cells (carries oxygen around the body)
3. Plasma: transports cellular waste
4. Platelets: helps blood clot
Name 3 effects of a force
1. Can make a stationary object move, or make a moving object move faster
2. Can change the direction of a moving object
3. Can slow down or completely stop a moving object
Name two methods to physically separate a mixture.
1. Decanting; when liquid is carefully poured off the top of a mixture into another container, leaving the sediment behind in the original container.
2. Sieving: To separate large particles from small particles by passing the mixture through a sieve.
How are sedimentary rocks formed?
When existing rocks have been weathered and eroded into sediments, these sediments are compacted together to form sedimentary rock.
Identify the roles of the liver and pancreas in the digestive system
Liver: produces bile, which helps the digestion of fats and oils
Pancreas: Produces enzymes which help break down food
Name one advantage and one disadvantage of fossil fuels.
Advantage: Energy efficient; generates a large amount of energy for a small amount burnt.
Disadvantage: They are a finite resource; the rate of consumption is greater than the rate of production.
What is an alloy, and name an example
An alloy is a combination of one or more metals, or metals with non-metallic elements. The resulting substance has different properties to its components.
Steel is made from a mixture of iron and carbon but is stronger than both of them
What does the atmosphere protect Earth from?
The sun's harmful radiation and meteors
What does a dialysis machine do?
Performs the functions of a kidney; filters the blood by removing extra salt and wastes, then returns clean blood to the patient's body.
What is chemical potential energy?
The energy stored in chemicals that is released when they undergo a reaction
What is carbonation?
When carbon dioxide in the air reacts with water to form a weak acid called carbonic acid.
How do we see the phenomenon of Auroras?
When charged particles from the solar wind become trapped in the Earth’s magnetic field, they collide with air particles above Earth’s magnetic poles, causing them to glow.
Why is cellular/organ transplantation important?
Give 3 examples
1. Bone marrow: treatment for those with Leukaemia
2. Blood transfusion: For those who have lost alot of blood due to heavy bleeding, or haemophilia
3. Liver: Some people may have their organs due to life habits such as smoking.
What do transformers do in distributing electricity across the country?
- Increase or decrease the voltage.
- We need to step down voltage from the powerlines as it is far too high safety wise and to use for home appliances.
Why are polymers important to society?
- We are very dependent on polymers.
Outline the current accepted scientific theory for the creation of the universe
The Big Bang theory states that the universe was created 14 billion years ago. The universe was inside a bubble that was smaller than a pinhead and was very hot and dense. Then it exploded, and the universe expanded and cooled over time.