Which of these is an example of a chemical change?

A. feeling ice melt on your skin

B. leaving cheese out to get moldy

C. smelling sprayed perfume

D. crushing ice with a hammer

Maria wants to determine which type of disinfectant kills the most bacteria. Which of the following is the best way for Maria to determine this? A. Ask ten different companies that make disinfectants which type is best. B.

The kind of hazardous waste disposal that most clearly resemble recycling is

Which statement is true about the properties of the majority of the elements in the far left column of the periodic table? A. They are highly reactive. B. They have no luster. C. They have low electrical conductivity. D.

A model of fossils formed on land, on the shore, and in water was set up in Ms. Bill's classroom. One of the students commented that the model gave her the wrong idea about the types of fossils found in each location.

Draw the structure of the compound C9H12 from its proton (1H) NMR spectrum below. First-order spin-spin splitting rules and equal coupling constants can be assumed.

Ten questions you would love to ask you guardian parents and teachers about happenings around the world right now

Moldear una plastilina es un cambio fisico o quimico.

Which is a correct statement of Newton's second law? An object in motion stays in motion, and an object at rest stays at rest unless acted upon by a net force.

The atomic number of an element is 71. is this element diamagnetic or paramagnetic?

J. C. wants to determine if there is a relationship between room color and sleep. Based on his research, J. C. makes an educated guess that people fall asleep more quickly in a room painted blue than in a room painted yellow.