Identify each of the following as either a physical change or a chemical change. Explain your answers.

A. a piece of wood is sawed in half.

B. milk turns sour.

C. melted butter solidifies in the refrigerator.

Phenylalanine hydroxylase is an enzyme that participates in the reaction to form tyrosine from phenylalanine. What problem would people have if they do not have this enzyme?

How does changing the number of protons compare to changing the number of neutrons in an atom

In general, the nucleus of a small atom is stable. Therefore, over very short distances, such as those in a small nucleus, a. the strong nuclear force equals the electric force. b.

What does tortoise eat

Choose all that apply. According to the theory of matter proposed by John Dalton: all matter is made up of atoms all atoms of the same element have the same mass all atoms of the same element have the same size combinations of atoms create chemical

How does the calorie compare to the metric unit the joule? How do you calculate a calorie? Is it the same for all types of food?

Under which conditions would the solubility of a gas be greatest? A. high pressure and high temperature B. high pressure and low temperature C. low pressure and high temperature D. low pressure and low temperature

How many milliliters is 0.55 L? O A. 1000 ml OB. 0.00055 mL O C. 550 ml D. 55 mL

When a warm front passes your location, the temperature rises rapidly. As a result, air density: B? increases decreases remains the same

A scientist wished to carry out a chemical reaction in which two moles of aluminum combine with three moles of sulfur. He has 2.70 g of aluminum to react. How many grams of sulfur must he take to satisfy all the aluminum atoms? 1.51 g 2.14 g 3.