Answer:
1. Balanced chemical for the given chemical reaction is :
number of mole of sulphuric acid produced = 12.5 mol
number of mole of oxygen required=6.25 mol
Explanation:
1. Balanced chemical for the given chemical reaction is :
from above balanced equation it is clearly that ,
2 mole of sulpher dioxide gives 2 mole of sulphuric acid
1 mole of sulpher dioxide gives 1 mole of sulphuric acid
therefore,
12 .5 mole of sulpher dioxide will givs 12.5 mole of sulphuric acid
number of mole of sulphuric acid produced = 12.5 mol
2 mole of sulphur dioxide needs 1 mole of oxygen gas
so,
1 mole of sulphur dioxide needs 0.5 mole of oxygen gas
therefore 12.5 of sulphur dioxide needs mole of oxygen
number of mole of oxygen required=6.25 mol
Answer: option B. The number of the outer most energy level for elements in that period
Explanation:
Answer:
The true statement about the discovery of electrons is :
C. Electrons were discovered in a vacuum tube
Explanation:
In 1870, Sir William Crookes developed the first cathode ray tube which have high vacuum inside.
These rays moved the paddled wheel when placed in their path.This means these rays have some momentum.
When the magnetic field was applied to the cathode rays they showed deflection. This means these cathode rays must have some charge because only charged particles can show deflection when place in magnetic field.
Later is was found by J.J Thomson that these are negatively charged.
How ?
We Know that like charges repel each other and unlike charges attract each other. This means if a particle has negative charge then it will attract the positive charge.
J.J Thomson studied these cathode ray tubes and found that these rays repels the negative charge particles .Hence these rays must be negatively charged.
He called these tiny Particle "electron"
The balanced reaction is: H2O2 -> H2O + (1/2) O2
However, this is a very awkward equation since it has a
coefficient in fraction form.
Another way to write this equation is:
2 H2O2 -> 2 H2O + O2
Hope this helps.
<h3>
Answer:</h3>
Lead-205 (Pb-205)
<h3>
Explanation:</h3>
<u>We are given;</u>
We are supposed to identify its product after an alpha decay;
- Polonium-209 has a mass number of 209 and an atomic number of 84.
- When an element undergoes an alpha decay, the mass number decreases by 4 while the atomic number decreases by 2.
- Therefore, when Po-209 undergoes alpha decay it results to the formation of a product with a mass number of 205 and atomic number of 82.
- The product from this decay is Pb-205, because Pb-205 has a mass number of 205 and atomic number 82.
- The equation for the decay is;
²⁰⁹₈₄Po → ²⁰⁵₈₂Pb + ⁴₂He
- Note; An alpha particle is represented by a helium nucleus, ⁴₂He.