Atoms have a positively charged nucleus
Ernest Rutherford
The subatomic particle not found in the nucleus of an atom
electrons
What is the mass number of Neon-21
21
one mole
6.022 x 1023
At the subatomic level, how do you identify an element
number of protons
JJ Thomson
The difference between two isotopes of the same element
number of neutrons
How many protons, neutrons, and electrons does nitrogen-15 have
7 p, 8 n, 7 e
molar mass
mass in grams per mole
The number of protons in an atom
atomic number
His theory also explained the Law of Conservation of Mass
Dalton
If you change the number of _____ the type of element will change
protons
What is the name (hyphen notation) of the isotope with 9 protons and 10 neutrons
Fluorine- 19
How many grams are there in 17.28 moles of carbon?
207.5 g
What is the densest region of an atom?
nucleus
determined the charge of the electron with an oil drop experiment
Milikan
the number of protons and neutrons in an element
Mass number
Why is carbon-12 not as heavy as carbon- 13
Carbon-13 has more neutrons
how do you convert moles to grams
multiply by molar mass
What is the approximate mass, in amu, of helium-3
3 amu
The number or atoms, molecules or particles in one mole of a substance
Avogadro
the average mass of the most abundant isotopes
atomic mass
How many neutrons, protons, and electrons does 124 54Xe have
70 neutrons, 54 protons, 54 electrons
how many atoms are in 57.2 g of Ar?
8.62x1023atoms
atoms are mostly ___________
empty space