Which of the following is low reacting or non-reactive elements?
a) alkaline earth metals
b) alkali metals
c) halogens
d) noble gases
Which of the following group elements have low melting and boiling point and are colorless, odorless, tasteless and non-flammable gases?
a) alkaline earth metals
b) alkali metals
c) halogens
d) noble gases
The number of proton is equal to……..
a) atomic number
b) mass number
c) nucleon number
d) atomic mass
In periodic table, where the atomic number of an element is written?
a) above the symbol
b) below the symbol
c) before the symbol
d) after the symbol
The atomic number of oxygen is eight. How many protons are present in an atom of oxygen?
a) 7
b) 8
c) 18
d) 32
The number of neutron is calculated by subtracting the ……..from mass number.
a) atomic number
b) mass number
c) atomic mass
d) nucleon number
