An 0.648 g sample of isobutene contains 0.556g of carbonand the rest is hydrogen. 0.5 mol of isobutene has a mass of 28.5g. what is the empirical formula and molecular formula?

Which is considered an indication that a chemical reaction or chemical change has taken place A:solid melts B: heat is given off C: substance dissolves D: Substance change shape

Disease causing bacteria need oxygen to survive. true or false

Which aspect is similar in both chemical and nuclear reactions? A. Both involve nuclear fusion. B. Both involve nuclear fission. C. Both may release heat and light. D. Both involve the exchange of electrons.

Identify the composition of caffeine. C8H10N4O2 * C=?, H=?, N=?, O=?

Cooler objects always have more thermal energy than warmer objects. True False

10) A screwdriver has the density of 5.5 grams per cubic centimeter. It also has the mass of 2.3 grams. What is the screwdriver's volume?

A chemist weighed out 20.7 g of sodium. Calculate the number of moles of sodium she weighed out

If 1.00 mol of argon is placed in a 0.500-L container at 20.0 ∘C, what is the difference between the ideal pressure (as predicted by the ideal gas law) and the real pressure (as predicted by the van der Waals equation) ? For argon, a=1.

Part 2: Finding Speed and Height Using Energy Directions: Use the KE and GPE equations to solve for speed or height depending on the situation. 1. A 1,000-kg car has 50,000 joules of kinetic energy. What is its speed? 2.

Why is conductivity be the best test to find a metal, non-metal or metalloid?