Chapter 2- Basic Chemistry Flashcards
Matter
Everything that takes up space and has mass
Elements
Make up all matter, living or non-living
Cannot be broken down into simpler substances with different properties
6 elements that make up 95% or living organisms
CHNOPS
Carbon Hydrogen Nitrogen Oxygen Phosphorus Sulphur
Atoms
Smallest unit of an element that retains the characteristics of that element
3 subatomic particles that make up an atom
Protons (+)
Neutrons
Electrons (-)
Persons and neutrons found in nucleus, electrons found in the orbitals
Information obtained from the periodic table
Atomic symbol (letter) Atomic number (#of protons, on top) Atomic mass (# of + and neutrons)
Mass - atomic # = # of neutrons
Periods vs groups
Periods= horizontal Groups= verticle
Electron arrangement
E- orbit nucleus in shells
- 1st shell holds up to 2 e-
- 2nd and 3rd hold up to 8 e- each
Valence shell
Outermost shell, determines the chemical properties of an atom
Octet rule
Atoms whose outer shells are not full interact with other atoms to acquire e-
The loss or gain of e- causes an atom to become charged (ions, + or -)
Compound
Combination of 2 or more elements
Tendency to form compounds depends on valence electrons
Chemical bonds
When atoms are held close together by attractions
3 types of chemical bonds
Ionic, covalent, hydrogen
Ionic bonds
- Transfer of e-
- Formed btw oppositely charged ions
- Metals and non metals
Covalent bonds
- sharing of e-
- strongest of the 3 bonds
- # that can be created depend on the VE
- # of bonds is equal to the # of e- needed to fill the outer shell
- non metals