BMG Year 9 Core Science Revision

Atom

The smallest unit of matter

Compound

A compound contains 2 or more different types of atoms chemically bonded to each other.

Molecules

A molecule contains two or more non-metals covalently bonded together.

Isotopes

Atoms with the same atomic number but different mass number/numbers of neutrons 

Ions

When an atom gains or loses electrons

Chemical change

A completely new substance is formed or the chemical composition of a substance is changed.

Polyatomic ion

Ions that contain more than 1 atom.

Neutralisation

Acid/base reaction

Biosphere

Zone on Earth in which all life exists

Hydrosphere 

All liquid including liquid, solid and vapour

Atmosphere

Layers of gases including air composition and weather system

Lithosphere

Solid earth including rocks, tectonic plates and land forms

Biomes

Regions within the biosphere 

Environmental factors that biomes are influenced by

Latitude, temperature and rainfall

Atmospheric Layers

Troposphere, stratosphere, mesosphere, thermosphere, exosphere

Functions of the atmosphere 

Regulates temperature, facilitates weather and climate patterns and protects life from solar radiation.  

Troposphere

6 - 17km above Earth's surface, contains 75% of the total mass of the atmosphere ad has the greatest influence on the weather.

Stratosphere

35-40km above Earth's surface, contains the ozone layer which allows visible and infrared radiation from the sun through and absorbs UV radiation reducing its damage on humans.

Carbon travels from

the non-living atmosphere to living things when carbon dioxide is absorbed by photosynthetic organisms

The nitrogen cycle

Represents how nitrogen moves throughout moves through the biosphere.

Nitrogen is important because

Our cells require it to make DNA and proteins such as enzymes and hormones and plants require it to make chlorophyll which is used for photosynthesis.

Weather VS Climate

Weather is short term and climate is long term

Carbon dioxide gas in the air …

traps heat in our atmosphere. This heat is absorbed by oceans, causing ocean temperatures to rise.

Cause of global warming

Burning fossil fuels such as coal and oil, along with deforestation, travel, industrial waste and increase in the human population