Which of the following statements is true? Temperature is an average measure of the heat energy in a substance.

The transfer of heat in a fluid does not require physical contact between molecules.

The sun's energy comes from the nuclear reactions of changing hydrogen into helium.
All of the above.

PLS HELP

Niobium forms a substitutional solid solution with vanadium. compute the number of niobium atoms per cubic centimeter for a niobium-vanadium alloy that contains 24 wt% nb and 76 wt% v. the densities of pure niobium and vanadium are 8.57 and 6.10 g/cm3, respectively

Two conductors, a and b, are each in the shape of a tetrahedron. but of different sizes. they are charged in the following manner: 1. tetrahedron a is charged from an electrostatic generator to charge q. 2. tetrahedron a is briefly touched to tetrahedron b. 3. steps 1 and 2 are repeated until the charge on tetrahedron b reaches a maximum value. if the charge on tetrahedron b was q/4 after the first time it touched tetrahedron a. what is the final charge qbmax on tetrahedron b?

Which of the choices are parts of an atom? select all that apply. a.) compound b.) electron c.) neutron d.) molecule e.) photon f.) proton g.) element