Answer:
Valence electrons are involved in Reaction B but not in Reaction A.
Explanation:
The description of reaction A in which protons are lost or gained by the atom of the element is a nuclear reaction. In nuclear reactions, the nucleons which are the protons and neutrons drives the reaction. No valence electrons in the orbiting shells are involved in this kind of reaction. During this type of reaction, an atom changes it identity to that of another.
Reaction B in which no identity change occurs is a chemical reaction. In chemical reactions bonds are formed by the atoms using the valence electrons that orbits round the central nucleus. The atoms remain the same but it chose to attain stability and an inert configuration by losing or gaining electrons.
That is called condensation
Answer:
No, in science their meanings are not the same as their everyday meanings.
Explanation:
In Science, Precision and Accuracy are defined as,
Accuracy:
Accuracy is the value which is closest to the known or standard value.
Precision:
While, Precision is the value of closeness of two measured values to each other.
Example:
Let suppose in Chemistry Lab you weight an object as 50 g. While the actual weight of that object is 30 g. It means your reading is not accurate.
On second measurement you find that the object weight is 31 g. This time your reading is not precise.
If a substance is not chemically pure, it is either a heterogeneous mixture or a homogeneous mixture. If its composition is uniform throughout, it is a homogeneous mixture.
