26 elements are man-made ..........
The answer is "<span>An atomic nucleus is positively charged because it is composed of protons". An atomic nucleus actually contains nucleons which are made up of both protons and neutrons. Since neutrons are neutral or have no charge, the charge of an atomic nucleus mainly relies on the positive charge of the protons.</span>
Answer:
Number of moles = 0.0005 mol.
Explanation:
Given data:
pH = 3
Volume of solution = 500 mL
Number of moles = ?
Solution:
HCl dissociate to gives H⁺ and Cl⁻
HCl → H⁺ + Cl⁻
It is known that,
pH = -log [H⁺]
3 = -log [H⁺]
[H⁺] = 10⁻³ M
[H⁺] = 0.001 M
Number of moles of HCl:
Molarity = number of moles / Volume in litter
Number of moles = Molarity × Volume in litter
Number of moles = 0.001 mol/L × 0.5 L
Number of moles = 0.0005 mol
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.
The answer to this question is A- evaporation
