Answer:
A) It tends to increase from top to bottom of a group
Any chemical reaction in which the oxidation number of an atom,molecule,or ion changes by gaining or losing an electron
Answer: Though a hydrogen atom has only one electron, it contains a large number of shells, so when this single electron jumps from one shell to another, a photon is emitted, and the energy difference of the shells causes different wavelengths to be released... hence, mono-electronic hydrogen has many spectral lines.
Explanation: sry its late
The amu is a unit which means the mass per neutron, So the 74.55 means the mass per mole KCl. So the mole number of 2.330g KCl is 2.330/74.55=0.031 mol. The volume is 0.031/0.1250=0.248 L ≈ 250 mL. So the answer is a.
There is 9.375 g of nitrogen. This is because when a half-life passes, the mass becomes 2 times less. Since two half-lives have passed, you need to divide by 4.