A chemical reaction that gives off heat is most likely to be

Which of the following substances is not a fluid? air iron water helium gas

The compound diborane can be used as a rocket propellant. What is the percent composition of boron in diborane (B2H6) ? A. 22% B. 25% C. 39% D. 75% E. 78%

How many atoms are in 3 moles of carbon?

An analysis for copper was performed on two pure solids. One solid was found to contain 43.0% copper; the other contained 32.0% copper. Could these solids be samples of the same copper-containing compound

Mothballs are comprised primarily of naphthalene (C10H8). When 1.025 g of Naphthalene burns in a bomb calorimeter, the temperature rises from 24.25 degrees Celsius to 32.33 degrees Celsius.

How many of the following elements have 2 unpaired electrons in the ground state? C Te Hf Si A) 1. B) 2. C) 3. D) 4.

Which has a higher frequency, a neutron or electron? Why?

1) Identify the intensive properties of a sample of matter: A. mass B. hardness C. color D. volume E. reflectivity

Suppose you have a buffer containing 0.400 M hydrazine and 0.300 M hydrazinium chloride at equilibrium. Then you add 25.2 g of NaOH to 2.0 L of the buffer. What change in pH is caused by the addition of the base? A) 0.99 B) 0.40 C) 8.71 D) - 0.36

The heart is an example of which level of organization within an organism? O cell organ tissue organ system O O