Because if you change two things then you do not know which one has affected or altered the dependent variable. if you only change one then you know what exactly changed and why
They are atoms. a molecule is made up of atoms.
Answer:
Li⁺
Explanation:
Li⁺ ions has a noble gas electron configuration because it resembles that of He.
To have a noble configuration, electrons in the outermost shell must completely fill their respective orbitals.
Li⁺ is an ion that has lost one electron from the usual number of 3 thereby remaining 2 electrons.
The electronic configuration is given as;
Li⁺ 1s²
The S orbital can hold a maximum number of just two electrons.
Helium atom has two electrons with electronic configuration of 1s²
Therefore Li⁺ = 1s² = He
