The table below gives the numbers of protons, electrons, and neutrons in four atoms. Atom Number of protons Number of neutrons Number of electrons
1 9 8 9
2 9 9 8
3 9 9 10
4 9 10 9

Based on the table, which atom has a charge of –1?
1
2
3
4

The atomic radius of sodium is 186 pm and of chlorine is 100 pm. the ionic radius for na+ is 102 pm and for cl– is 181 pm. in going from na to cl in period 3, why does the atomic radius decrease while the ionic radius increases? a. the inner electrons in the sodium cation shield its valence electrons more effectively than the inner electrons in the chloride anion do. b. the inner electrons shield the valence electrons more effectively in the chlorine atom than in the chloride anion. c. the outermost electrons in chloride experience a smaller effective nuclear charge than those in the sodium cation do. d. the outermost electrons in chloride experience a larger effective nuclear charge than those in the sodium cation do. e. monatomic ions are bigger than the atoms from which they are formed.

Which of these expressions are correct variations of the combined gas law? p1v1t2 = p2v2t1 both

One nanometer is equal to how many meters?