Why are water molecules polar? select one:

a. they contain two kinds of atoms.

b. the electrons in the covalent bonds spend more time closer to the oxygen nucleus.

c. the hydrogen bonds are weak.

d. they have covalent bonds?

Consider a sample containing 0.740 mol of a substance. How many atoms are in the sample if the substance is lead?

Which of these statements about enzymes is true? a.) enzymes increase the rate of a reaction by decreasing the gibbs free energy change of the reaction. b.

A patient comes into the hospital because she is worried about possible exposure to radiation. The doctors determine that the patient has 60 rem of exposure. What is her risk of cancer? High because her exposure is less than 100 rem.

6. Substance through which current can flow without change in its composition is called: A. Semi-conductor B. Insulator C. Resistor D. Conductor

Which of the following are density labels? Kg/L g/m g/mL cm/g

What factors allowed the koala population to grow beyond what their habitat could sustain?

What are the subscripts for the molecular formula of C2H3

What does the dashes line represent? A. Medium B. Boundary C. Normal D. Incident Ray

Only a small amount of cerium oxide nanoparticles is needed because the nanoparticles ... 1) are elements 2) are very reactive 3) have a high surface area to volume ration

Describe the solubility of water compared to ethanol?