Answer:
identical atom in which an electron moves from the first to the third shell.
Atoms may occupy different energy states. The energy states are discrete, i.e. they occur at specific values only. Therefore an atom can only move to a new energy level if it absorbs or emits an amount of energy that exactly corresponds to the difference between two energy levels.
The lowest possible energy level that the atom can occupy is called the ground state. This is the energy state that would be considered normal for the atom.
An excited state is an energy level of an atom, ion, or molecule in which an electron is at a higher energy level than its ground state.
An electron is normally in its ground state, the lowest energy state available. After absorbing energy, it may jump from the ground state to a higher energy level, called an excited state.
Wen a liquid turns into solid it loses thermal energy
D freezing
During a scientific study a hypotheses is generally modified or discarded
so for first blank the answer is hypotheses
Now in case of phlogiston theory it was assumed that when a substance catches fire it evolve certain substances known as phlogiston which was later on discarded as there is no such particle. Infact a substane undergoing oxidation may gain weight
Hence in second blank the answer is new evidence didn’t support it,
Magnesium, strontium and barium are a few of the elements that have the same properties as calcium. elements found in group 2 of the periodic table have similar properties to it.
A chemical bond that is formed when two atoms share electrons is called a covalent bond :)
