After three half-lives, what fraction of a radioactive sample remains.

One person is pushing to the right with force of 10 N The other person is pushing to the left with a force of 7 N which of the following best describes the movement of the table?

The limiting reactant in a chemical reaction is the reactant that a. is used up at the end of the reaction. b. is left over after the reaction. c. has the largest number of atoms. d. has the fewest number of atoms.?

Which is the separation technique that identifies parts of a mixture based on how fast different compounds move across a material? a. filtration c. chromatography b. distillation d. crystallization

Rank these elements according to highest ionization energy. Be, C, O, Ne, B, Li, F, N

A scientist is studying a chemical reaction. She predicts that after the reaction the product will have less chemical potential energy than the reactants had originally

What is called what a scientist personal opinion affects the way experimental results are reported? A. Bias B. Classifying C. Inductive reasoning D. Procedure

Coffee is decaffeinated industrially using supercritical (sc) CO2. One advantage to using scCO2 is that the polarity of the supercritical fluid can be tuned by varying temperature, pressure and cosolvent additives.

The relationship between pressure and temperature of a gas, when volume and moles of a gas are held constant, is: P*T = k. TRUE FALSE

The system is said to be in dynamic equilibrium when: Select one: a. there is no longer any net change in the concentrations of products or reactants. b. the forward and reverse reactions come to a halt. c. None of these d.

You have a 1 L container of a gas at 20 C and 1 atm. Without opening the container, how could you tell whether the gas is chlorine or fluorine? a. measure the mass of the gas b. measure the speed of the gas molecules c.