Answer:
Option B. +3 and +6
Explanation:
<em>Zeff</em> = <em>z - s</em>
where <em>z</em> is the atomic number, <em>s</em> is the number of shielding(non-valence) electrons
For Boron, electronic configuration is 1s²2s³.
z = 5, s = 2
Zeff = 5 - 2 = +3
For Oxygen, electronic configuration is 1s²2s²2p⁴
z = 8, s = 2
Zeff = 8 - 2 = +6
Answer:
When the metal reacts with hot, concentrated sulphuric acid, the products of the reaction are copper (II) sulphate, sulphur dioxide and water. Cu + 2H2SO4 = CuSO4 + SO2 + 2H2O. This is a typical redox reaction in which the acid is reduced to SO2, but no hydrogen is produced here
Stars on the main sequence fuse hydrogen into helium via a six-stage sequence of reactions
Answer:
a. Solar
Explanation:
Solar energy causes water to evaporate, which is the driving force of the water cycle. Water from the ocean evaporates and comes back down as rain and it gives life to the Earth and so it continues.
