A reaction releases 489.34 J of heat how many calories of heat is that equal to 1 cal equals 4.186 J

Brittney was babysitting for her neighbor's two-year-old and had just put little Justin down for a nap.

Darin skateboarded to the north at 7 m/s. In 5 seconds, he slowed down to 6 m/s. What was his acceleration? A. 0.2 m/s2 north B.-0.2 m/s2 north C. 5 m/s2 north D.-5 m/s2 north

What is the solution of the following equation. 2x+7+5x=7 (x+8) A. no solution B. infinitely many solution C. x=56 D. x=7

1) How many moles are in 25.0 grams of water? 2) How many grams are in 4.500 moles of Li2O? 3) How many molecules are in 23.0 moles of oxygen? 4) How many moles are in 3.4 x 1023 molecules of H2SO4? 5) How many molecules are in 25.

what is the acceleration of gravity if the force is 390000 N abd the Mass is 9000 kg (also what formula do you use for this?)

Does skin have a nucleus true or false

Bacteria are only found in decaying matter. A. True B. False

Which is considered a chemical mutagen? tanning beds tobacco X-rays precious metals

Combining 0.380 mol Fe2O3 with excess carbon produced 13.7 g Fe Fe2O3 + 3C → 2Fe + 3CO What is the actual yield of iron in moles? What is the theoretical yield of iron in moles? What is the percent yield?

When a hydrogen electron makes a transition from n=3 to n=1?