Answer: 
Explanation:
Alpha Decay: In this process, a heavier nuclei decays into lighter nuclei by releasing alpha particle. The mass number is reduced by 4 units and atomic number is reduced by 2 units.
General representation of an element is given as: 
where,
Z represents Atomic number
A represents Mass number
X represents the symbol of an element
General representation of alpha decay :
The balanced nuclear equation when the isotope Strontium-90 decays by Q- decay is :
Answer:
D) 
Explanation:
Carbon.
The electronic configuration is -
Thus, 2s orbital is fully filled and p orbital can singly filled 3 electrons. Thus, Carbon has 2 singly occupied orbitals.
But in methane, 
it forms 4 bonds. So, 1 electron each from 2s orbital jumps to the next orbital in the p subshell.
Thus, the configuration is:-
Thus, the valence electron configuration is:-
Yes, Sharpies contain volatile solvents—and when inhaled these solvents can produce a "high." The effects of inhalants (including Sharpies) can be similar to those of alcohol and include slurred speech, lack of coordination, euphoria, and dizziness.
1:1
Fe has a charge of 2+ while O has a charge of 2-.
Formula: FeO
