1. 2.1 – Matter all objects are made of matter
~ something with mass and volume (remember the density lab?)
matter can usually be found on Earth as a solid, liquid, or a gas

2. atoms are made up of smaller parts:
atom: building block of all matter
atoms are made up of smaller parts:
proton: particle that has a positive (+) charge
~ large in size
neutron: particle that has no charge (neutral)
~ large in size (like a proton)

3. electron: particle that has a negative (-) charge
~ very small
~ about 1/1800th the size of a proton or neutron
atoms have no overall charge (neutral) because there is an equal number of protons (+) and electrons (-)

5. nucleus: center of atom ~ contains protons and neutrons
electron cloud: area of space that surrounds the nucleus
~ contains the
electrons
electron cloud
nucleus

6. Happy, happy Carbon atom! But, are all parts really happy?

7. element: substance that can’t be broken down into a simpler form elements are organized by their properties on the periodic table (p.36) 95 naturally occurring elements with only 8 making up most of Earth’s crust

9. ~ hydrogen = H, carbon = C, oxygen = O
element symbols are usually 1 or 2 letters
~ hydrogen = H, carbon = C, oxygen = O
each element has a different number of protons
~ hydrogen (H) = 1, carbon (C) = 6, oxygen (O) = 8
number of protons is called the atomic number of the element

11. in nature, there can be several versions of the same element same number of protons BUT have a different number of neutrons ~ called isotopes some isotopes are unstable and give off neutrons which makes them radioactive

12. Hydrogen 2 (Deuterium) –
Hydrogen – 1 P, 0 N
Hydrogen 2 (Deuterium) –
1 P, 1 N
Hydrogen 3 (Tritium) –
1 P, 2 N
radioactive isotope

13. isotopes of the same element are shown by writing the symbol and the mass number
~ H-1, H-2, H-3
mass number: total number of protons and neutrons in an atom
~ remember those are the two particles with any measurable mass
~ electrons are too small!

14. Hydrogen 2 (Deuterium) –
Hydrogen – 1 P, 0 N
H-1
Hydrogen 2 (Deuterium) –
1 P, 1 N
H-2
Hydrogen 3 (Tritium) –
1 P, 2 N
H-3

15. The NEW Periodic Table
Read the lyrics to follow along!

16. compound: substance made from atoms of 2 or more different elements
atoms are held together by a force called a chemical bond
arrangement of electrons determines how atoms bond together

17. electrons in the electron cloud are grouped in different energy levels
each level can hold a limited number of electrons
outer level can hold 8 electrons (except for H and He)
~ is stable with outer level full

18. if the outer level ISN’T full, the atom will bond with other atoms to get a total of 8 in the outer shell

19. sometimes atoms will lose or gain electrons in order to get a total of 8 electrons in their outer shell
atoms will then have a charge due to an unequal number of electrons (-) and protons (+)
~ those atoms are called ions

20. atoms that lose electrons are positive ions (more P than e)
atoms that gain electrons are negative ions (more e than P)
opposite charges attract so an ionic bond forms between opposite ions, creating crystalline ionic compounds

23. covalent bond: when atoms share electrons to form a covalent compound
since the number of protons (+) is equal to the number of electrons (-), the charge of the molecule is neutral (no charge)

25. metallic bond: when atoms share electrons between many metal ions

26. metal ions are positive so are attracted to the negative electrons
because many ions are sharing many electrons, metals have unique properties:
easily shaped (malleable)
drawn into thin wires
conduct heat and electricity