Krypton: Non-metal, inert gas
Zirconium:Metal, Transittion metal
Magnesium: Metal, Alkaline Earth metal
Chlorine: non-metal, halogen
Arsenic: semi-metal a.k.a metaloid
Helium: non-metal, inert gas
Oxygen: non metal
Copper: metal, transition metal
Silicon: non metal, metaloid
Aluminium: Metal, post-transition metal
Hope that helps.
A would be the answer to this question
4- N
8- H
2-S
Or in 4 nitrogens, 8 hydrogens, and 2 silicons
Answer:
Various limitations of Mendeleev's periodic table are:-
Position of hydrogen - he couldn't assign a correct position to hydrogen as it showed properties of both alkali and halogens .
Position of isotopes - he considered that the properties of elements are a function of their atomic masses. Hence isotopes of a same element couldn't be placed.
In the d-block , elements with lower atomic number were placed before higher atomic number.
Explanation:
Answer:
1 . 
2. 
Explanation:
The more stable the ionic compound, the more is it lattice energy.
- The more the charge on the cation and the anion, the greater is the lattice energy.
- The less the size of the cation and the anion, the greater is the lattice energy.
Scandium oxide (
) is an oxide in which 
behaves as cation and 
behaves as anion.
The compounds which has higher lattice energy than scandium oxide are:
1 .
This is because the charge are same on the cation and the anion as in the case of the Scandium oxide but the size of the cation 
is smaller than . Thus, this corresponds to higher lattice energy.
2.
This is because the charge on the cation 
is greater than that of and also the size of the cation is smaller than . Thus, this corresponds to higher lattice energy.
