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 :

Ionic compounds are the combination of two elements, one of which is a metal, while the other is a nonmetal. The intermolecular forces binding them is called an ionic bond. To name an ionic compound, take the name of the metal element first, followed by the nonmetal, but adding the suffix -ide. For example, NaCl is named as sodium chloride.
There are a total of 4 elements
Answer:
Plants are found in the domain of eukarya