Answer:
When atom undergoes the alpha emission the original atom convert into the atom having mass number less than 4 and atomic number 2 less than the starting atom.
Explanation:
Alpha radiations are emitted as a result of radioactive decay. The atom emit the alpha particles consist of two proton and two neutrons. Which is also called helium nuclei. When atom undergoes the alpha emission the original atom convert into the atom having mass number less than 4 and atomic number 2 less than the starting atom.
Properties of alpha radiation:
Alpha radiations can travel in a short distance.
These radiations can not penetrate into the skin or clothes.
These radiations can be harmful for the human if these are inhaled.
These radiations can be stopped by a piece of paper.
₉₂U²³⁸ → ₉₀Th²³⁴ + ₂He⁴ + energy
Mass equals density times volume
Because D=m/v
Multiply by v
Dv=m
Answer:
(c) P and Sb
Explanation:
We can determine the number of valence electrons of an element:
- If it belongs to Groups 1 and 2, the number of valence electrons is equal to the number of group and the differential electron occupies the s subshell.
- If it belongs to the groups 13-18, the number of valence electrons is equal to: "Number of group - 10" and the differential electron occupies the p subshell.
Which pair of elements have the same valence electronic configuration of np³?
(a) O and Se. NO. They belong to the group 16 and the valence electron configuration is ns² np⁴.
(b) Ge and Pb. NO. They belong to the group 14 and the valence electron configuration is ns² np².
(c) P and Sb. YES. They belong to the group 15 and the valence electron configuration is ns² np³.
(d) K and Mg. NO. They belong to the groups 1 and 2 and the valence electron configuration is ns¹ and ns².
(e) Al and Ga. NO. They belong to the group 13 and the valence electron configuration is ns² np¹.
Answer:
n₂ =1.4 mol
Explanation:
Given data:
Mass of nitrogen = 2 g
Initial Volume occupy by nitrogen = 1.25 L
Final volume occupy by nitrogen = 25.0 L
Final number of moles = ?
Solution;
Formula:
V₁ / n₁ = V₂ / n₂
Number of moles of nitrogen:
Number of moles = mass/ molar mass
Number of moles = 2 g/ 28 g/mol
Number of moles = 0.07 mol
Now we will put the values in formula:
V₁ / n₁ = V₂ / n₂
n₂ = V₂× n₁ /V₁
n₂ = 25 L × 0.07 mol / 1.25 L
n₂ = 1.75 L. mol / 1.25 L
n₂ =1.4 mol
The answer is H20 thank me later
