Air is the example of mixture
Elements in the periodic table are arranged in the increasing order of their atomic number.
An atom will contain equal amount of protons and electrons. If two elements are in same period of periodic table then these elements will have same number of electrons.
Helium is one of the seven elements which are called as noble gases. This gas is odorless, tasteless and colorless which makes it unique from other elements.
It has two valence electrons while atoms of other elements in the group have 8 valence electrons.
Lithium has one valence electron, while calcium atom has 2 valence electrons.
The highest level of energy is due valence electrons of an atom. The correct answer is Lithium.
Fluorine element has 9 electrons. There are 2 electrons in the first energy level and seven electrons in the second energy level.
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Answer:
Answer:B
Explanation:
Because it all stayed consistant
