Please help me ! Which two elements have similar properties?

A. Sodium (Na) and Rubidium (Rb)
B. Sodium (Na) and Magnesium (Mg)
C. Hydrogen (H) and Neon (Ne)
D. Carbon (C) and Phosphorus (P)

Aplane travels 1000 miles in 5 hours .what is the planes average speed?

What is the final velocity of the initial velocity of 25 and -50?

Photoelectrons with a maximum speed of 6.50 x 107 m/s are ejected from a surface in the presence of light with a frequency of 6.75 x 1014hz. if the mass of an electron is 9.10 x 10-31 kg, calculate in joules the maximum kinetic energy of a single electron. 3.84 x 10-15 j 1.92 x 10-15 j 5.92 x 10-23 j 3.07 x 10-16 j