Answer:
E²⁺
Explanation:
The group two contain alkaline earth metals.
There are six elements in group 2A.
Beryllium, Magnesium, calcium, strontium, barium and radium.
All members have two valance electrons.
They lose two valance electrons to complete the octet.
When they lose the two valance electrons they form cation X²⁺.
They react with halogens and form salt such as
MgCl₂, CaCl₂ etc.
Mg²⁺ Cl²⁻₂
The oxidation state of halogens are -1, while the elements of group two A shows +2 that's why two atoms of halogen are combine with one atom of alkaline earth metals and make the compound overall neutral.
All the alkaline earth metals have similar properties.
<u>Answer:</u> The atomic mass of these species is different and atomic number remains same.
<u>Explanation:</u>
Isotopes are the chemical species of the same element having different number of neutrons.
- Atomic number is equal to the number of protons or electrons present in that element.
Atomic Number = Number of electrons = Number of protons
- Atomic mass is defined as the sum of number of protons and neutrons contained in an atom.
Atomic Mass = Number of protons + Number of neutrons
For isotopes, as the number of neutrons differ, the atomic mass also differs.
For Example: Carbon has 3 naturally occurring isotopes: 
. The atomic number remains the same but atomic mass differs.
Hence, for isotopes, the atomic mass of these species is different and atomic number remains same.
Answer: Option (a) is the correct answer.
Explanation:
Transmutation involves the conversion of one chemical element into another chemical element. This change occurs when an element or isotope passes through a number of reactions. It is a natural process and happens when there is a radioactive decay.
Hence, it is also a nuclear change as it occurs when there is a change in the nucleus of an atom. As this change can be due to the nuclear decay so as a result there will be some change in energy also. It is the process where one element converts into another using bombardment with high energy particles.
Thus, we can conclude that transmutation involves is a nuclear change.
A binary ionic compound is composed of ions of two different elements - one of which is a metal, and the other a nonmetal.
