Pure substances:

Elements & compounds (1 type of atom)

Pure substances:

Elements & compounds (1 type of atom)

Mixtures:

Homogeneous (solutions) & heterogeneous (mechanical mixtures)
(combination of substances without chemicaly bonding)

Mechanical Mixture

combination of 2 or more substances that are visibly distinct

Solution:

all of this is a mixture
(homogeneous mixture of one or more solutes dissolved in a solvent)

Particle Theory of Matter

1. All matter is made of particles.

2. Particles have space between them.

3. Particles are always moving.

4. Particles move faster when heated.

5. Particles attract each other.

States of Matter

• Solid: Definite shape & volume.

• Liquid: Definite volume, no definite shape.

• Gas: No definite shape or volume.

Physical vs. Chemical Changes

• Physical: Change in appearance (melting, boiling).

• Chemical: New substance formed (burning, rusting).

Characteristic Physical Properties

• Density, boiling/melting point, solubility, conductivity, magnetism.
  
  (js properties to identify shit)

Element

pure substance, cannot be broken down into simpler substances chemical substances

Compound

A pure substances made of different elements (that are chemically combined)(H20)

Non-metals:

An element, usually a gas or a powdery solid, that does not conduct heat or electricity
(not have the properties of metals)

above staircase (group 14-16)

Metaloid:

An element that has properties of both metals and non-metals
(found on staircase)

metal

element that has lustre, is a conductor, and is malleable and ductile
(everything left and below staircase)

Groups (columns):

Similar properties.

Periods (rows)

number of energy levels (electron shells) stays the same
number of protons and electrons increases.
(left-right)

Chemical family

A column of elements with similar properties
(perodic table)

Alkali Metals

group 1 of PT
(1+)

Alkaline Earth Metals

group 2 of pt
(2+)

Transition metals

group 3-12

Poor metals

group 13-16 under staircase

Halogens

group 17

Noble Gasses:

Group 18

outer valence electon # for groups

• Group 1 → 1 valence electron

• Group 2 → 2 valence electrons

• Groups 13 to 18 → subtract 10 from the group number to get valence electrons

Dalton atom theory

• Atoms are invisible.

Thomson atom theory

Electrons in atoms (plum pudding).
(electons inside positive charged orb)

Rutherford atom theory

Nucleus in atom.
nucleus surrounded by electrons

(mostly empty space in atom)

Bohr atom theory

Electrons orbit nucleus in shells.

Isotopes

atoms of the same element
same number of protons
but
different number of neutrons.

Reactivities of Metals

Reactivity increases as you go down a group (left to right from all groups)
so Alkali metals (Group 1) are most/very reactive and the last group is least/not reactive

what happeneds when u go down a group (family)

down each group (family) (electron shells) increases

Trends in the periodic table

• Across a row: Atomic number increases, atomic radius decreases

• Down a column: The atomic radius increases, the density increases

  
  

How Atoms Combine:

become more stable, usually filling outer electron shells.
They do this by sharing or transferring electrons, forming bonds.

Covalent Bonding:

Between: Two non-metal
SHARE ellectonns

Ionic Bonding:

Between: A metal and a non-metal
STEALING

metal loses electron
non metal STEALS electons

Bohr-Rutherford Diagram: how to draw kinda

label amount of p and n in the “nucules” draw the shells and draw electons in pairs of 2 max and rings 2, 8, 8, 18

What is Static Electricity

Build-up of electric charge on a surface.

Charging by Contact (Conduction):

Transferring charge by touching a charged object to a neutral one.

Charging by Friction

Transferring electrons by rubbing two materials together.

Charging by Induction

Charging an object without touching it, by bringing a charged object near and causing electrons to rearrange.

temporary, since like repell, it repell the like chargres which leaves the remaining chargres that it is attracted to.

Electric Discharge:

The sudden release of built-up static charge (e.g., lightning or a shock).

Current electricity

flow of electric charge (electrons) through a conductor in circuit

how electons flow

Electrons flow from the negative terminal to the positive terminal of a power source.

Electric Circuits

A closed path that allows electric current to flow from a power source, through a load, and back.

Electric Energy

energy carried by moving electric charges (usually electrons) through a conductor

Direct Current

Electrons flow in one direction only

Alternating Current

Electrons switch direction back and forthGenerating current electricity

ectromagnetic induction

when a magnetic field changes around a conductor
causes electrons in the conductor to move
(move wire around magnet)

Potential difference (volage)

energy per charge between two points in a circuit

V = I x R

Measuring voltage and current in circuits (with tools)

voltmeter = volts (parrellel connection)
ampmeter = current (series connection)

Resistance in circuits

Resistance in circuits is the property of a material or component that slows down the flow of electric current. It resists the movement of electrons. V = I x R

Biosphere

where life exists

lithosphere

Earth’s solid outer layer

Atmosphere

The layer of gases surrounding Earth.

Hydrosphere

all water on earth

Energy Flow in Ecosystems

sun-producers-consumers-decomposers

Energy decreases at each step 10% moves to each level

photosynthesis formula

6CO₂ + 6H₂O + light energy → C₆H₁₂O₆ + 6O₂

cellular respiration formula

C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O + energy (ATP)