A. Uni-negative
B. Uni-positive
C. Di-negative
D. Di-positive

A. Same number of neutrons
B. Same mass number
C. Same physical properties
D. Same chemical properties

A. High energy electron beam
B. ? – particle
C. X-rays
D. All of the above

A. H+ H H-
B. Li+ Na+ K+
C. C1- Br- I
D. F- Ne Na+

A. 1.6 x 10-27 kg
B. 1.6 x 10-24 kg
C. 1.6 x 10-26 kg
D. 1.6 x 10-28 kg

A. Mass number
B. Atomic mass
C. Relative abundance
D. all of the above

A. NaCl
B. H2O
C. CCI4
D. It can be applied to all mentioned above

A. lighter
B. intermediate
C. heavier
D. are collected at same time

A. different number of protons
B. same number of neutrons
C. different number of neutrons
D. same mass number (nucleon number)

A. sand
B. haemoglobin
C. diamond
D. maltose