Answer:
Alpha particle or helium nuclei.
Explanation:
Alpha particle:
Alpha particle is 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 less than 2 as compared to parent atom 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
Answer:
36 KJ of heat are released when 1.0 mole of HBr is formed.
Explanation:
<em>By Hess law,</em>
<em>The heat of any reaction ΔH for a specific reaction is equal to the sum of the heats of reaction for any set of reactions which in sum are equivalent to the overall reaction:</em>
H 2 (g) + Br 2 (g) → 2HBr (g) ΔH = -72 KJ
This is the energy released when 2 moles of HBr is formed from one mole each of H2 and Br2.
Therefore, Heat released for the formation of 1 mol HBr would be half of this.
Hence,
ΔHreq = -36 kJ
36 KJ of heat are released when 1.0 mole of HBr is formed.
3 cubic centimeters, Volume= density/ mass
Answer:
1-Find the molar mass of the substance.
2-H3PO4
3-New atoms are created.
4-The ratios of the number of moles of each substance that react and that are produced.
5-conservation of mass
6-The number of atoms for every element is equal on both sides of the equation.
7-1:1
8-1:03
9-5.50%
Answer is: <span>an atomic radius.
</span>The atomic radius<span> of a </span>chemical element<span> is a measure of the size of its atom.
</span>The atomic radius varies with increasing atomic number, but usually increases because of increasing of number of electrons.
The atomic radius decreases across the periods because an increasing number of protons, because <span>greater attraction between the protons and electrons.</span>
