If a piece of pure iron is placed in pure nitrogen, nothing happens. If the iron is exposed to air, it begins to rust. What conclusion can you make about air, based on this observation?

One's experience of the world depends mostly on what two factors? A. an individual's physical health and stimuli encountered in the environment B. the psychological state of mind of an individual and stimuli not attended to C.

What is the type of symbiosis of tiny organisms called mites live in human eyelashes and feed on dead skin without harming humans

What is the purpose of the fruit that develops on a flowering plant

All organisms exhibit variations

Suzanne has a cat and uses a pet carrier to take her cat to the veterinarian. After a few years, the cat runs away and hides every time Suzanne gets the carrier out. Which best describes the cat's behavior? A. instinct B. reflex C. conditioned D.

Egg laying land animals have evolved to produce eggs with tough shells to ensure that

Which of the following statements describes a proton of an atom? A has a negative charge and is located in the nucleus. B has no charge and is located in the nucleus C has a positive charge and is located in outer energy levels.

What are reasons scientists use models? To study objects far away To study objects too large To study objects too small. To study objects easily found in a lab. To study events that take place over long periods of time.

1. true false Carbon atoms form the building blocks of most living things.

Inhibiting enzymes involved in cell wall synthesis leads to which of the following? A) cell death by osmotic lysisB) a reduction in protein synthesisC) the incomplete synthesis of the bacterial cell wallD) a reduction in the amount of usable energy