Yes, that is all correct!
The atomic number is the same as the number of protons (12).
Magnesium = Mg
Atomic mass is 24. 305.
In the physical properties, it is mentioned that the element has 4 valence electrons. The elements in the periodic table are arranged such that, the number of valence electrons present in the neutral atoms belonging to a particular group is equal to the group number.
Thus, the unidentified element can be best classified as a nonmetal in period 4
Ans C)
Answer:
Double replacement reaction
Explanation:
This is what is known as a double replacement reaction. The two parts of each molecule separate and recombine to form two new compounds. For instance, 
separates into 
and 
, while 
separates into 
and 
, and then they recombine with the other compound.
Hope this helps!
Element 87 francium have the highest atomic size, so in short the closest element to francium have the high atomic size.
Answer:
acquired/harmful
Explanation:
This type of mutation and exposure will cause indefinite problems.
