Answer: loss of electrons
Explanation:
An atom is made up of three subatomic particles named protons neutrons and electrons. An atom forms positive ion with the loss of at least one electron.
For instance: Calcium with atomic number 20, and electronic configuration 1s2, 2s2 2p6, 3s2 3p6, 4s2 will lose the two outermost electrons to form a divalent positive ion (Ca2+).
Ca --> Ca2+ + 2e-
Thus, loss of electrons is the change to an atom that occurs when it forms a positive ion
Answer:
More energy will be released from the old substance than the new substance will need to form it's chemical bonds.
Explanation:
Given
Chemical A and Chemical B react in an exothermic reaction.
This means energy is released when they react to give products. The product formation also requires energy, which is got from the energy released when A and B reacts. The energy that is left after the formation of products is released as heat. So in order for a reaction to be exothermic, the energy released by the reactants should be more than the energy required for the new chemical bonds to be formed to give the products.
Contradictory observations are found