How many atoms are there in 5.7 mol of hafnium?

3. A mass of 0.15 ounces is equal to how many grams? A. 0.2352 g B. 0.24 g C. 4.25 g D. 4.3g E. None of the above are correct.

Some polymers are elastic because they are made of a. carbon. c. sugar and alcohol. b. phosphate ladders. d. cross-linked chains.

Which of the following statements is true? A. Some chemical reactions release energy, but no chemical reaction can absorb energy. B. Some chemical reactions absorb energy, but no chemical reaction can release energy. C.

A 54.2 L sample of gas at 115 K is heated to 345 K, at constant pressure. What volume does the gas now occupy?

A sample of 1.44 g of helium and an unweighed quantity of O₂ are mixed in a flask at room temperature. The partial pressure of helium in the flask is 42.0 torr, and the partial pressure of oxygen is 159 torr. What is the mass of the oxygen?

Which of following statements is true about scientific knowledge? Scientific ideas are not subject to change, so scientific knowledge stays the same. Scientific knowledge is constantly evolving as new observations are made.

Why is ice cream a mixture

Which of the following is a type of cell organelle? A. membrane B. cytoplasm C. DNA D. nucleaus

Electromagnetic forces are the predominant force in holding what subatomic particles together?

When in a compound, the oxidation number of a nonmetal: A). is always fixed and can never be changed B). can only be deduced once all the other oxidation numbers in the equation are totaled C).