Answer is: selenium (Se).
1) electron configuration: ₃₄Se 1s²2s²2p⁶3s²3p⁶3d¹⁰4s²4sp⁴.
2) ₃₃As 1s²2s²2p⁶3s²3p⁶3d¹⁰4s²4sp³.
3) ₃₆Kr 1s²2s²2p⁶3s²3p⁶3d¹⁰4s²4sp⁶.
4) ₃₁Ga 1s²2s²2p⁶3s²3p⁶3d¹⁰4s²4sp¹.
Valence electrons of selenium are 4s²4sp⁴.
Melting points and boiling points of molecular compound are usually lower than ionic compounds. This is so as only a small amount of energy is required to overcome the weak intermolecular forces of attraction (Van de Waals forces) thus having lower m.p. and b.p.
Ionic compounds require a large amount of energy to overcome the strong electrostatic forces of attraction between the ions, hence having higher mp and bp
Answer:
C. C, because it’s the highest of all four and C is 2,5 which is medium but the highest one.
A. 2.9384 x -7
B. 9.0832 x 9
C. 3.4455 x -3
D. 2 x 3
I a chemical reaction, we have the reactants in the left part,followed by an arrow and then the products.
So, the reactants are the two that are in the left part of the equation:
Sodium hydroxide and Hydrochloric acid