mass # atomic # protons + neutron s = proton s = Atomic Symbols
Jan 21, 2016
mass #
atomic #
protons +
neutrons=
protons=
Atomic Symbols
Element AtomicNumber
Protons Neutrons Electrons
19 19 20
S 17
39Ca
14 6
K 19 1939
16 16 161633
20 20 19 2020
66 86 C
Elements are identified by atomic number (protons).
11H
21H
31H
protium deuterium tritium
element:mass:
_________:
same or differentsame or different
same # of protons & electrons,
BUT different # of neutrons
Isotopes
1. The number of protons in the nucleus is…
A. the mass number.
B. the atomic number.
C. the same as the number of neutrons.
D. the total of protons and neutrons.
Quick (but challenging) Quiz!
2. The mass number is…
A. the number of protons.
B. the number of neutrons.
C. the total of protons and electrons.
D. the total of protons and neutrons.
Quick (but challenging) Quiz.
3. Isotopes of an element have…
A. the same mass number.
B. different atomic numbers.
C. the same number of protons but different mass numbers.
D. the same number of protons but different numbers of neutrons.
Quick (but challenging) Quiz.
4. How many neutrons are in an atom of potassium–40 ? (40K)
(Atomic Number = 19)
A. 19 neutrons
B. 21 neutrons
C. 40 neutrons
D. 59 neutrons
Quick (but challenging) Quiz.