Structure of An Atom Notes

6 Elements that are needed for living things ____________ ____________ = 96% of the Human Body CHNOPS CHNO

6 Elements that are needed for living things ____________

____________ = 96% of the Human Body

Atoms = ________________________ ________________________ = has all the characteristics of that element = ________________________ ________________________ smallest particle of an element basic building block of all matter

Atoms = ________________________

________________________

= has all the characteristics of that element

= ________________________ ________________________

PROTONS positive ( p+ ) Neutrons neutral ( n ° ) NUCLEUS e- e- e- e- e- e- e- e- e- Electron cloud ELECTRONS negative ( e- )

All nuclei are _________ because of the ________. Each element has a different number of _________ positive protons protons

All nuclei are _________ because of the ________.

Each element has a different number of _________

e- e- 2 8 18 Energy Levels NUCLEUS Energy Levels e- e- e- e- e- e- e- e-

2 6 Example: Oxygen = 8 e- NUCLEUS e- e- Energy Levels e- e- e- e- e- e-

O The # of p+ in nucleus Determines which element an atom is = the total # of particles an atom Atomic Number 8 15.9994 Atomic Weight

The # of p+ in

nucleus

Determines which

element an atom is

O Atomic Number Atomic Weight then if you ROUND You will get the… Mass Number = the sum of p+ and n ° Number of Neutrons = Mass # - Atomic # 8 15.9994 = + MASS NUMBER Number of p+ Number of n °

O So, why is this a decimal? It is an average of all the isotopes! What’s an isotope? 8 15.9994

The Nuclei of 3 isotopes of H+ PROTIUM DEUTERIUM TRITIUM + + + 1 PROTON 1 PROTON 1 NEUTRON 1 PROTON 2 NEUTRONS Atoms that have the same # of p+ but different # of n ° Definition

Example of Compounds: Water Carbon Dioxide NaCl C6H12O6 HCl NH4 Substance with atoms of 2 or more elements that are chemically combined Compounds =

Example of Compounds:

Water

Carbon Dioxide

NaCl

C6H12O6

HCl

NH4

Atoms come together when the result is more ________ than the individual atoms stable e- e- 2 8 18 If filled to capacity then it is STABLE NUCLEUS e- e- e- e- e- e- e- e-

How do they fill energy levels? 1) BY SHARING ELECTRONS 2) BY GAINING OR LOSING ELECTRONS

How do they fill energy levels?

1) BY SHARING ELECTRONS

2) BY GAINING OR LOSING ELECTRONS

Method One: sharing electrons Example: Hydrogen unstable sharing electrons is called "covalent bonding" H e- H H e- e-

H H O stable & happy! H20 = water Examples of Molecules with Covalent Bonding: sugars, fats, proteins, & water

MOLECULE = group or atoms held together by a covalent bond Examples of Molecules with Covalent Bonding: sugars, fats, proteins, & water water

MOLECULE = group or atoms held together by a covalent bond

Method Two: gaining or losing electrons An atom (or group of atoms) that gains or loses electrons = ION = (charged particle) If I lose a negative electron then I will become more positive If I gain an electron then I will become more negative

An atom (or group of atoms) that gains or loses electrons = ION = (charged particle)

Na Cl Na Cl 11 e- 11 p+ 17 e- 17 p+ + unstable unstable

Na Cl ionic bond Ionic bond = attractive force between 2 ions of opposite charge stable

MIXTURE Combination of substances in which the individual components retrain their own properties Can be separated Ex: chex mix SOLUTION Mixture in which 1 or more substances (solutes) are distributed evenly in another substance (solvent) Ex: Jello

MIXTURE

Combination of substances in which the individual components retrain their own properties

Can be separated

Ex: chex mix

SOLUTION

Mixture in which 1 or more substances (solutes) are distributed evenly in another substance (solvent)

Ex: Jello