To find<span> the </span>valence electrons in an atom<span>, identify what group the element is in. An element in group 1A has 1 </span>valence electron<span>. For example, Li is in group 1A, so that means it has one </span>valence electron. If the element is in group 2A, then it has two valence electrons<span>.</span>
Answer:
D. It is a chemical reaction because the total mass remains the same when new substances are formed.
Explanation:
A chemical reaction is represented by a chemical equation which show the reactant and products. Reactants are written on left side of arrow while products are written on right side. The number of atoms are remain same however arrangement of atoms is different on both side.
For example:
6H₂O + 6CO₂ + energy → C₆H₁₂O₆ + 6O₂
it is known from balanced chemical equation that 6 moles of carbon dioxide react with the six moles of water and created one mole of glucose and six mole of oxygen. The number of atoms are same on both side however arrangement of atoms is different.
While in case of nuclear reaction small change in mass take place.
Atomic number of C is 6. Hence, there are 6 electrons in carbon.
The electronic configuration of carbon is 1s2, 2s2, 2p2
Here, there are 2 unpaired electron. However, C2+ ions have 2 electrons less as compared to C.
Hence, electronic configuration of C 2+ ion is 1s2, 2s2. All the electrons are paired in this system. So there are no unpaired electrons in C 2+ ion.
The answer is B the flow of electrons through a substance
