Atoms of elements that are in the same group have the same number of

a. protons.

c. valence electrons.

b. neutrons.

d. protons and neutrons.

What has a greater effect on an object's kinetic energy---doubling its mass or doubling its speed? Explain

1. Is O2 a compound? Explain. 2. Is O2 a molecule? Explain. 3. State the law of conservation of matter, and give an example demonstrating its meaning. 4. Electrolysis is used to break liquid water into hydrogen and oxygen gas.

Suppose you are studying two stars. Both stars have the same apparent magnitude, but star A has a greater absolute magnitude than star b. What can you tell about the distance from Earth of these two stars?

Methane is a major component of coal, wood, uranium, or natural gas?

Derivative for tan (x)

At what speeds do you criuse down the track of a roller coaster

A sample of hydrogen gas is mixed with water vapor. The mixture has a total pressure of 755 torr and the water vapor has a partial pressure of 24 torr. What amount (in moles) of hydrogen gas is contained in 1.55 L of this mixture at 298 K?

Both equation I and II are balanced, but equation II is the correct way to write the balanced equation. Why do you think this is? (Hint: Think fractions.) I) 2 SnO2 + 4 H2 → 2 Sn + 4 H2O II) SnO2 + 2 H2 → Sn + 2 H2O

If some of the salt remains adhered to the weighing paper (and therefore is not transferred to the calorimeter), will the enthalpy of solution for the salt be reported too high or too low?

In one process, 5.95 kg of caf2 is treated with an excess of h2so4 and yields 2.45 kg of hf. calculate the percent yield of hf.