Sun

Important:

• Nuclear fusion: Hydrogen atoms violently collide with each other, fusing and forming a helium atom, causing huge amounts of energy to be released. This happens because of the extreme conditions in its core.

• Sunspot: Darker patch on the sun’s surface caused to them being darker than the rest of the surface.

• Core: Hottest part of the sun, located in the centre

• Radiative Zone: largest part of the sun, where energy is transferred to surface by conduction and radiation diffusion.

• Photosphere: The suns outer shell, from which you can see visible light emanating from

• Chromosphere: Hot atmosphere of the Sun

Diagrams:

Fig a.

Periodic table 

Organisation

• The periodic table is organised by groups (columns) and periods (rows).

• The same group means they have the same number of valence electrons.

• Ordered by increasing atomic number.

• The more to the right, the less metallic the element.

What does an element look like 

What does each part tell you about the element

• Atomic number: number of protons or electrons (number of protons = number of electrons) 

• Atomic mass: number of protons plus neutrons

Atoms, Elements, Compounds, Mixtures, Molecules

Atoms:

• Atoms are the building blocks of all matter.

• They have no overall charge.

Subatomic particles

More notes

• Protons and neutrons are much bigger then electrons

• Having too many neutrons makes an atom unstable

Elements:

• An element is a pure substance containing only one type of atom.

Compounds:

• A compound is a substance containing two or more types of atoms chemically bonded

Mixture: 

• A group of substances mixed together that arent chemically bound

Molecule: 

• A molecule is 2 or more atoms chemically bonded

  • A molecule of an element is a molecule with only one type of atom

  • A molecule of a compound is a molecule with two or more different types of atoms

Ions

• Ions are atoms or groups of atoms that have an electric charge. 

• When there are more electrons, there is a negative charge, and when are are more electrons, there is a positive charge.

• Ions are notated like this: 

Ionic compounds

• Atoms bond to form Ions to form a full valence shell of either 2 or 8.

• The pattern for electron arrangement (for the first 20 electrons) is 2, 8, 8.

For example: Lithium and Flourine: Lithium has electron: 2,1 whereas Fluorine has electrons 2,7. Therefore, lithium gives its electron to fluorine, bonding them both. Lithium is now a positive ion, Fluorine a negative one. 

Atmosphere

What is the atmosphere

• The atmosphere on Earth is made up of mostly nitrogen, oxygen, and water vapour. Carbon dioxide and Argon are also present.

Levels

• Troposphere: Temperature decreases with altitude

  • Convection currents occur. 

• Stratosphere: Temperature increases with altitude,

  • Ozone layer: O3 molecules break down UV rays and disperse heat.

• Mesoshere: Temperature decreasing with altitude

  • Where meteoroids burn

• Thermosphere: Temperature increasing with altitude

  • Aborbs heat from UV rays to increase temperature

Exosphere: Fringe of atmosphere where particles can escape