Chaper 4 - Chemical Foundations Flashcards
(7 cards)
0
Q
What are the 5 main ideas of Dalton’s atomic theory
A
- elements are made of atoms
- all atoms of a given element are identical
- atoms of one element are different from those of another element
- the law of constant composition
- atoms are not created nor destroyed, simply changed in the way they are grouped
1
Q
Describe the law of constant composition
A
a given compound always has the same composition regardless of where it came from
2
Q
What is a compound?
A
a distinct substance composed of two or more elements that always has the same relative mass
3
Q
What are the rules for writing formulas?
A
- each atom present if represented by it’s element symbol
- the number of each type of atom is indicated in a subscript
- when only one atom is present, no subscript is written
4
Q
What are isotopes?
A
atoms with the same number of protons but different numbers of neutrols
5
Q
The number of protons in a nucleus is called the atom’s _____________
A
Atomic number
6
Q
The sum of the number of neutrons and the # of protons in a given nucleus is call the atom’s ______________
A
mass number
