According to the nebular hypothesis, our solar system formed from a huge rotating cloud made mostly of
a. carbon and hydrogen.
b. helium and hydrogen.
c. oxygen and helium.
d. nitrogen and oxygen.

Which of the following statements is true? question 4 options: nuclear decay rates vary with the conditions of the reaction, but chemical reaction rates do not. chemical reaction rates vary with the conditions of the reaction, but nuclear decay rates do not. neither chemical reaction rates nor nuclear decay rates vary with the conditions of the reaction. both chemical reaction rates and nuclear decay rates vary with the conditions of the reaction.

What element breaks down into yttrium-90?

Three alkali metals in group 1 are a. calcium, strontium, barium b. boron, aluminum, gallium c. sodium, potassium, rubidium d. fluorine, iodine, chlorine