Why does a person's heart rate increase during exercise?

(1) Less oxygen is needed.

(2) More oxygen is needed.

(3) Less carbon dioxide is needed.

(4) More carbon dioxide is needed

Select the choice that best completes the following sentence. Simple machines A. cannot be combined to make compound machines. B. are tools that make work easier. C. reduce the amount of energy needed to do work. D.

If a doughnut contains 1.8 moles of sugar (C6H12O6), how many sugar molecules are in a box of one dozen doughnuts?

What is the molarity of a solution containing 501mL with 35g NaCl

Write the chemical formulas for the ionic compound vanadium (v) oxide

What is the chemical formula for ammonium carbonate? (NH4) 2CO3 (NH4) HCO3 NH4 (CO3) 2 NH4 (CO3)

Which of the following statements is true? Selected Answer: D. At least two of the above statements (A-C) are true. Answers: A. Ions are formed by adding or removing protons or electrons. B. Scientists believe that solids are mostly open space. C.

Does anybody know which element from the periodic table that has 19 electrons and 24 neutrons, for atomic charge.

Given the following reaction 2Al + 3Cl2 - -> 2AlCl3 How many grams of AlCl3 aluminum chloride will be produced from 125 g of Al and 125 g of Cl2?

Potassium chlorate (used in fireworks, flares, and safety matches) forms oxygen and potassium chloride when heated. KClO3 (s) → KCl (s) + O2 (g) [unbalanced] What mass of oxygen gas is formed if 26.4 g of potassium chlorate decomposes completely?

Explain the iodine clock reaction.