Chemistry MCQS

441. The symbol for krypton is:
a) Kr
b) Xe
c) Rn
d) He

442. The symbol for xenon is:
a) Kr
b) Xe
c) Rn
d) He

443. The symbol for radon is:
a) Kr
b) Xe
c) Rn
d) He

444. Which noble gas is used in some types of deep-sea diving to prevent nitrogen narcosis?
a) Helium
b) Neon
c) Argon
d) Xenon

445. Noble gases are used in neonatal incubators because they are good:
a) Insulators
b) Conductors
c) Reflectors
d) Moderators

446. Which noble gas is used in some types of fluorescent lamps to produce a greenish glow?
a) Helium
b) Neon
c) Argon
d) Krypton

447. Atom number of protons are equal to?
(A) Number of electrons
B) Number of protons
(C) Number of neutrons
(D) None of the above

448. Ions gain which charge when electrons are added?
(A) Positive charge
B) Negative charge
(C) Becomes neutral
(D) All are correct

449. Ions gain which charge when electrons are removed?
A) Positive charge
(B) Negative charge
(C) Becomes neutral
(D) All are correct

450. An atom is how many times bigger than the nucleus?
(A) 1000
(B) 5000
(C) 8000
D) 10000