Which of the following is a physical change?

A. magnetzing an iron rod

B. roasting marshmallows on a campfire

c. milk souring

D. an antacid neutralizing stomach acid

A small amount of a solid unknown compound was placed into a test tube containing isopropanol. The solid floats on top of the liquid isopropanol. Is this unknown compound considered to be soluble or insoluble?

Do you think people use drugs to heighten consciousness or to escape from it?

Which of the following statements supports the concept that organisms are still evolving? The increasing population of humans. The decreasing number of fossils found in rock. The increasing need for new antibiotics and medicines.

An alloy is a mixture of metals. Suppose that a certain alloy is made by mixing 50 grams of an alloy that contains 52% copper with 78 grams of pure copper. a). How many grams are in the resulting mixture? __grams. b).

A student reads that blood is a liquid component of the human circulatory system. It is composed of mainly plasma and red and white blood cells. Blood transports nutrients, waste materials, and gases to all parts of the body.

Which of the following is a physical change? A. magnetzing an iron rod B. roasting marshmallows on a campfire c. milk souring D. an antacid neutralizing stomach acid

Which of the following objects would require the use of a large-scale model? An atom A car engine A frog's heart The Mississippi River

What is the empirical formula for C5H1102? * A. C10H2202 B. C5H110 C. C5H1102 D. C2H110

How is the energy level of an atom's valence electrons related to the period in the periodic table?

In the presence of a platinum catalyst, ammonia, NH3, burns in oxygen, O2, to give nitric oxide, NO, and water vapor.