1. all living things are composed of cells
2. cells are the basic building blocks of life
3. All cells are created by preexisting cells
1. it increases then decreases i.e +1, +2, +3, +4, +5, -2, -1 then 0.
2. group 6 elements have more valence electrons than group 2.
3.fluorine is the most reactive because reactivity and electronegativity reduces down the group.
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Answer:
im guessing it's the second one
Answer:
The electron configuration for this atom is Calcium, which has 2 valence electrons.
Explanation:
Following the periodic table and with the electron configuration, you will end up with calcium, which has 2 valence electrons. (Always follow the electron configuration from left to right! It begins at hydrogen, then to helium... and so on.)
1s2 -> He....
2s2 -> Be....
2p6 -> Ne...
3s2 -> Mg...
3p6 -> Ar...
4s2 -> Ca.
