Download MAKE-UP ACTIVITY/QUIZ NAME: Date: SHORT ANSWERS: Are all

MAKE-UP ACTIVITY/QUIZ
NAME:
Date:
I.
SHORT ANSWERS:
1. Are all atoms of the same element identical? If not, how do they differ?
2. Why are atomic masses of elements not in whole numbers?
3. Helium has two naturally occurring isotopes, helium-3 and helium-4. The
atomic mass of helium is 4.003 amu. Which isotope is least abundant in
nature? Explain.
4. What happens to the mass number of a radioactive atom when it emits an
alpha particle? A beta particle? A gamma particle?
II. TABLE COMPLETION: Fill in the missing information below.
1.
Isotope
Number of
protons
Number of
Electrons
Number of
neutrons
Atomic
number
Sodium-23
Lithium-7
Carbon-12
Carbon-14
Tin-119
Tin-120
2.
Particle
Symbol
α
4He
Mass (amu)
Charge
2
β
γ
1/1840
0
3.
Element Number
of
electrons
N
7
Cs
56
Br
35
Sb
51
Zn
30
Electron configuration
Valence electron
III. MULTIPLE CHOICE: Choose the letter of the correct answer
1. Which of the following is true about the isotopes of an element?
A. The same mass number
B. The same number of electrons
C. The same number of protons but different number of electrons
D. The same number of protons but different number of neutrons.
2. One of the isotopes of the element X has 20 protons and has a mass number of
40. How many protons, neutrons and electrons does this element have?
A. 20,20,20
C.
40,20,20
B. 20,20,40
D.
40,40,60
3. The diagram represents the nuclei of four different atoms A, B, C, and D. Which
two atoms are isotopes of the same element?
Key:
A
proton
B
neutron
C
For numbers 4-6: Choose among the following rules:
D
A. Aufbau’s principle
B. Periodic law
4.
5.
6.
C.
D.
Pauli’s Exclusion Principle
Hund’s Law of Multiplicity
Each orbital can accommodate only two electrons and these must have opposite
spins.
Electrons normally occupy the orbital in the lowest available energy level.
Electrons must occupy orbitals singly first before pairing and have parallel spins
in orbitals of the same energy level.
Assume that the following are 3 isotopes of element Kh exist: 224Kh, 220Kh, 228Kh.
If the atomic mass of Kh is 225.11, which of its isotopes is the most abundant in
nature?
A. 224Kh
B. 220Kh
C. 228Kh
D. All are equally abundant
7.
8.
Which among the following is the reason for the greatest amount of radioactivity
a normal human receives in the course of a year (excluding any medical/dental X-rays)?
A.
B.
C.
D.
9.
A.
B.
C.
D.
cosmic radiation from space
the land, food, and water
smoke detectors in the home
watching TV too many hours a day
Which of the following matches for scientist-discovery is correct?
Roentgen - X-Rays
Becquerel - electrons
Curies - radioactivity
Thomson - neutrons
10. Which of the following is true about radioactivity
A.
An emission radiation which is always accompanied by a chemical process.
B.
An emission radiation which is is always preceded by a chemical process.
C.
An emission radiation which is is initiated by absorption of radiation.
D.
An emission radiation which is is initiated by absorption of heat.