PLEASE PLEASE PLEASE HELP FAST!! NO LINKS! In the equation:

2H₂ + 1O₂ →→ 2H₂O

If you change the 2H₂ to 3H₂ molecules and balance the equation, which statement is correct?

A. The result of the equation will be the same.

B. The equation will produce three molecules of water.

C. It is not possible to produce water without leftover molecules.

D. Each oxygen molecule will combine with 2 hydrogen molecules with no leftover molecules.

What is the result of multiplying (2.5 × 1010) × (2.0 × 10-7)? a. 5.0 × 103 b. 5.0 × 10-3 c. 5.0 × 1017 d. 5.0 × 10-17

Cryolite, na3alf6(s), an ore used in the production of aluminum, can be synthesized using aluminum oxide. start this question by first balance the chemical equation.1.) balance the equation: - alo3(s)+naoh(l)+hf(> na3alf6+h2o(g). 2.) if 17.5 kilograms of al2o3(s), 51.4 kilograms of naoh(l), and 51.4 kilograms of hf(g) react completely, how many kilograms of cryolite will be produced? 3.)which reactants will be in excess, (al2o3, naoh, or hf) 4.)what is the total mass of the excess reactants left over after the reaction is complete in kg?

Structure of the atoms: discovery of the nucleus in 1909i need answering all of these questions