Download Year 9 Vocabulary

YEAR 9 SCIENCE VOCABULARY - ACCELERATED
For the end of year examination students must be able to match the following terms and definitions and they should
be able to write the definitions word for word.
KEY WORDS – Chemistry Matters
Term
Definition
Matter
A substance that occupies space and has mass.
Element
A substance composed of only one type of atom.
Compound
A substance made of two or more different atoms chemically combined.
Mixture
A substance made of two or more different elements or compounds that are not chemically
combined.
Atom
The smallest part of a chemical element that cannot be broken down by chemical means.
Electron
A negatively charged (-1) sub-atomic particle with negligible mass.
Proton
A positively charged (+1) sub-atomic particle with a mass defined as 1.
Neutron
A sub-atomic particle that has no charge (0) and has a mass defined as 1.
Atomic Nucleus
The centre of an atom. It is composed of protons and neutrons and possesses most of the
mass.
KEY WORDS – Plants and Animals
Term
Photosynthesis
Definition
The process where plants use carbon dioxide, water and energy from light to produce their
own food (glucose) and oxygen.
Fertilisation
The physical joining of male (sperm) and female (ova or ovule) gametes.
Chloroplast
Structure in plant cells that contains chlorophyll; site of photosynthesis.
Respiration
The process where plants and animals use oxygen to break down sugars (in food) to release
energy and carbon dioxide.
Mitochondria
Organelle that is the site of respiration.
Species
Adaptation
Natural selection
DNA
A group of organisms that share similar features, biological processes, and behaviours, and
are capable of inter-breeding with each other.
A physical feature, biological process or behaviour that an organism has that allows it to
survive and reproduce.
The process by which traits become more or less common in a population due to
differences in the survival and reproductive success of those that possess them.
A self-replicating material present in all living organisms that determines their genetic
characteristics.
Chromosome
Threadlike structure made of DNA that contains genes.
Gene
A short length of DNA that carries the genetic code for the production of a specific protein.
Allele
An alternative form of a gene. They can be dominant or recessive e.g B or b
KEY WORDS – Seeing into the dark
Term
Definition
Light
A type of energy that can be detected by the human eye.
Day
The time it takes for a planet to rotate on its axis (24 hours on Earth)
Year
The time taken by a planet to complete one orbit around a star.
Season
Solar system
A period during the year where the weather and day length is determined by the tilt of the
Earth and its stage of orbit around the Sun.
The system that includes the Sun plus all the celestial objects which are in the Sun’s
gravitational field.
Light year
The distance that light travels in 1 year.
Galaxy
A distinct collection of billions of stars held together by the force of gravity.
KEY WORDS – Energy in Motion
Term
Definition
Force
A push or a pull, measured in Newtons (N).
Mass
The amount of matter in an object, measured in grams (g) or kilograms (kg).
Weight
The effect of gravity on an object’s mass. Measured in Newtons (N).
Balanced forces
Forces are equal in size and opposite in direction.
Unbalanced
forces
The forces acting on an object are unequal, causing a change in motion.
Acceleration
The rate of change in velocity over time. Measured in ms-2.
Friction
A force that resists the motion of one material against another.
Energy
Energy is the capacity to do work
Kinetic energy
The energy an object possesses due to its motion.
Gravitational
potential energy
The energy an object has due to its position in a gravitational field.