In which type of chemical reaction do two or more substances combine to form one substance?

A cylinder rod formed from silicon is 46.0cm long and has a mass of 3.10kg. The density of silicon is 2.33g/cm3. what is the diameter of the cylinder?

Which choice is a pair of isomers? a. CH₃CH₂OH and CH₃OCH₂CH₃ b. 1-heptene and 2-methylhexane c. NCCH₃ and CH₃CNCH₃ d. CH₂CH₂CH₂CH₂CH₃ and CH₃CH₂CH₂CH (CH₃) ₂ e. methanol and ethene

How did an early understanding of gases lead to a better understand of the atom

How many megagrams are there in 7.020 * 10^-10 nanograms

The tendency of an element to react is closely related to? A. its atomic mass B. attractions between its atoms C. the number of valences electrons in atoms of the element D. the ratio of protons to neutrons in atoms of the element

List two things you know about nonrenewable energy

Does a mole of hydrogen have the same mass as a mole of oxygen? explain your answer.

A 0.500-L sample of H₂SO₄ solution was analyzed by taking a 100.0mL aliquot and adding mL of. After the reaction occurred, an excess of ions remained in the solution. The excess base required mL of for neutralization.

Ammonia can be prepared by the reaction of magnesium nitride with water. The products are ammonia and magnesium hydroxide. Write and balance the equation.

Which period is the shortest in the long form of the periodic table? Name all the elements in this period.