Answer:
One of the most common methods used today to determine the composition of stars is <u>spectroscopy</u>.
Explanation:
Spectroscopy is the study of the interaction between matter and electromagnetic radiation as a function of the wavelength or frequency of the radiation.
Potential energy is the energy possess by an object place on the top of table
Answer:
The answer to your question is given below.
Explanation:
Data obtained from the question include:
Sodium, Na => 1s2 2s2 2p6 3s1
Magnesium, Mg => 1s2 2s2 2p6 3s2
Aluminium, Al => 1s2 2s2 2p6 3s2 3p1
Sodium has 1 valence electron. If we remove the valence electron, sodium metal will become an ion. Thus, the electronic configuration becomes
1s2 2s2 2p6.
Magnesium has 2 valence electrons. If we remove the valence electrons, magnesium metal will be an ion. Thus, the electronic configuration becomes
1s2 2s2 2p6.
Aluminium has 3 valence electrons. If we remove the valence electrons, aluminum metal will become an ion. Thus, the electronic configuration becomes
1s2 2s2 2p6.