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Questions in chemistry

[Done] An athlete with a high count of red blood cells will perform well in tests of physical endurance because (a) waste products will be removed from the body easily. (b) excess levels of glucose will increase levels of respiration. (c) the reduced plasma volume will lower carbon dioxide levels. (d) high levels of oxygen will be available to the muscles.

[Done] A metal with a mass of 44 grams is dropped into 118.2 cm\(^3\) of water and sinks to the bottom. The volume of the water and object is 124.3 cm\(^3\). What is the density of the metal?

[Done] An antacid tablet containing 0.50 g of NaHCO3 is dissolved in 250 mL of water. What is the molar concentration of NaHCO3 in the solution?

[Done] Which physical state of matter exhibits the greatest change in volume with changes in temperature or pressure?

[Done] A hydrogen-filled balloon was ignited, and 1.60 g of hydrogen reacted with 12.8 g of oxygen. How many grams of water vapor were formed? (Assume that water vapor is the only product.)

[Done] Scientists use the Celsius scale as the SI unit of temperature. True or False

[Done] Is it possible to make a CD without plastic? Why or why not?

[Done] What is the chemical agent mixed with feces to determine if blood is present?

[Done] Explain how the number of valence electrons in atoms relates to their bonding with other atoms to form molecules.

[Done] When the equation ZnS + O\(_2\) → ZnO + SO\(_2\) is balanced, what is the coefficient of O\(_2\)? A. 1 B. 5 C. 3 D. 2