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

In a candy factory, the nutty chocolate bars contain 22.0% by mass pecans. If 5.0 kg of pecans were used for candy last Tuesday, many pounds of chocolate bars were made?

What element has a molar mass of 30.974 g/mol

How does the number of molecules in 1 mol of oxygen compare with the number of molecules in 1 mol of nitrogen? 1 mol of oxygen has fewer molecules. 1 mol of oxygen has more molecules. Each sample has the same number of molecules.

The number of positive charges in the nucleus of an atom is equal to to an altitude where the pressure is 380 mmHg and the temperature is 54°C

Helium in a 100 L container at a pressure of 65.6 atm and temperature of 250 K is transferred to a container with a volume of 250 L and a temperature of 300 K. What is the new pressure?

Suppose you find a rock that contains some potassium-40 (half-life of 1.3 billion years). you measure the amount and determine that there are 5 grams of potassium-40 in the rock.

What are some positive and negative effects of the production of maple syrup on society and the environment?

Describe and give an example of parasitism.

Why is a dilute solution of oleic acid used instead of pure oleic acid?

The vapor pressure of benzene (C6H6) is 73.0 mm Hg at 25 °C. What is the vapor pressure of a solution consisting of 179 g of benzene and 0.217 mol of a nonvolatile nonelectrolyte?