What do you think caused the balloon to expand

The law of the conservation of mass must be obeyed in a chemical reaction. what do the atoms do during a reaction that shows they obey the conservation of mass?

23492u undergoes alpha decay. what is the atomic number of the resulting element. express your answer numerically as an integer.

How many moles of water can be obtained from the reaction of 4 moles of O2?

In an exothermic reaction, why does the chemical reaction give off energy in the form of heat or light? A) Energy is created in the chemical reaction. B) The reactants are more stable than the products.

When Kay added 30 g of hydrochloric acid (HCl) to 65 g of Zn, bubbles appeared and a white precipitate, zinc chloride (ZnCl2) was produced. She found that the mass of the zinc chloride was 63 g.

Find the number of moles of water that can be formed if you have 134 mol of hydrogen gas and 62 mol of oxygen gas

The amount of kinetic energy an object has depends on its. motion position gravity height

What is the empirical formula of Fe?

Small beads of iridium-192 are sealed in a plastic tube and inserted through a needle into breast tumors. If an Ir-192 sample has an initial activity of 560 dpm, how much time is required for the activity to drop to 35 dpm (t1/2 = 74 days) ?

Consider the following equation. 2H2 (g) + O2 (g) 2H2O (g); ΔH is negative. Which statement is true? The reaction is endothermic from left to right. Increased pressure would increase the rate of forming water vapor.