D. In columns 3-12 in the centre of the table
Answer:
Both have the same amount of particles.
Explanation:
From Avogadro's hypothesis, we understood that 1 mole of any substance contains 6.02×10²³ particles.
This implies that 1 mole of Hydrogen contains 6.02×10²³ particles. Also, 1 mole of oxygen contains 6.02×10²³ particles.
Thus, 1 mole of Hydrogen and 1 mole of oxygen contains the same number of particles.
→ 
Explanation:
- The products formed are chromic chloride and cobalt.
Chromium + Cobaltous Chloride = Chromic Chloride + Cobalt
- Type of reaction is Single Displacement (Substitution) which is there is a displacement of one atom.
Reactants used in the reaction are -
- Chromium

- Cobaltous Chloride

Products formed in the reaction are -
- Chromic Chloride

- Cobalt

Hence, the chemical reaction is as follows -
→
For balancing the above chemical equation we need to add a coefficient of 2 in front of chromium and of 3 in front of cobalt(II)chloride on right-hand-side while of 2 in front of chromium chloride and of 3 in front of carbon monoxide on left-hand-side of the equation.
Hence, the balanced equation is -
→ 
Electrons, everything is pretty much based around the likeliness of electrons to be swapped or shared between atoms