-
Protons
positive charge, inside of the nucleus
-
neutrons
neutral charge, inside of the nucleus
-
electrons
negative charge, outside of nucleus (cloud)
-
NOTE: The charge depends on the sharing of electrons. Giving up electrons leads to a positive charge and gaining electrons leads to a negative. The number of protons in an atom remains unchanged.
-
Atomic number of an atom
the number of protons in its nucleus as well as the number of electrons that surround the nucleus of a NEUTRALLY CHARGED atom
-
What is the atomic number of carbon?
6
-
Mass number of an atom
the sum of its protons and neutrons
-
Isotopes have the same atomic number (same number of protons) but different mass numbers bc they have different numbers of neutrons.
Examples of isotopes?
- 12C (6 protons, 6 neutrons)
- 13C (6 protons, 7 neutrons)
-
14C
- Naturally occuring carbon contains trace amounts of it
- Radioactive
- Half life (the time it take for one half of the nuclei to decay) is 5730
-
Atomic Weight of a naturally occuring element
the average mass of its atoms.
-
Getting the atomic weight of Carbon
- (0.9889*12.0000) + (0.0111*13.0034) = 12.011
- We got this because we are going of the average mass of its atoms. These atoms are 12C, which has12.000 amu and makes up 98.89% of naturally occuring atoms and 13C, which has 13.0034 amu and makes up 1.11% of naturally occuring carbon.
-
Atomic Mass Unit
exactly 1/12 of the mass of 12C (whose atomic mass is 12). Therefore carbon would contain 12 atomic mass units.
-
Molecular Weight of a compound
the sum of the atomic weights of all the atoms in the molecule
|
|