Physical Properties & Quantities
What is the SI unit of length?
Metre (m)
Light travels in a ____ line.
Straight
What is the basic unit of life?
The cell.
What are all substances made of?
Particles.
What is the center of an atom called?
Nucleus.
Name the instrument used to measure volume of a liquid.
Measuring cylinder
What happens to light when it hits a mirror?
It will reflect.
Name the jelly-like substance in a cell.
Cytoplasm.
What happens to particles when a substance is heated?
They gain energy and move faster.
Name the three subatomic particles.
Proton, neutron, electron.
Explain how to ensure an accurate reading using a measuring cylinder.
Place it on a flat surface and read the bottom of the meniscus at eye level.
Why do shadows form?
Light cannot pass through opaque objects.
State two differences between plant and animal cells.
Plant cells have a cell wall while animal cells do not.
Plant cells have a large central vacuole while animal cells have small temporary vacuoles.
Plant cells usually have chloroplasts while animal cells do not.
Describe the movement and arrangement of particles in a liquid.
Closely packed but not in fixed positions; able to slide over one another.
What is a molecule? Give one example.
Two or more atoms chemically bonded.
E.g. O2, H2OHow do you find the volume of an irregular solid?
Using the displacement method, by measuring how much water is displaced when the object is submerged.
Define reflection and refraction.
Reflection: bouncing off a surface. Refraction: bending of light as it passes from one medium to another.
What does the mitochondria do?
It generates energy / carry out cellular respiration.
Use the particlulate model of matter to explain diffusion.
Particles move randomly and spread out from areas of high to low concentration.
Explain how ions are formed and why group 18 elements do not form ions.
Ions are formed when atoms gain or lose electrons to achieve a full valence electron shell. Because group 18 elements already have a full valence electron shell, they do not gain or lose electrons to form ions.