Which of these is an element?

A) air

B) Carbon dioxide (CO2)

C) water (H20)

D) carbon (c)

Which of the following is not a significant threat to the worlds' rainforest? a. grazzing b. logging c. agriculture d. shipping

The amount of moisture in the air is called

A student builds a circuit that lights a lightbulb. A second bulb is added to the same loop between the first bulb and the battery. Which statement describes the brightness of each bulb? Each bulb will be dimmer than the first bulb was.

Which term names the two dimemisional plane in which mars orbit the sun

How is the pH of an acidic substance raised?

What is the molar mass of the following substance : Cs2CO3

What does the velocity of a wave describe

Sulfur (S) has 16 protons and 16 neutrons. How many electron shells does an element of sulfur have?

Which one of the following statements about orbital energies is incorrect? A) The energy of a given orbital increases as the nuclear charge Z increases. B) In many-electron atoms the energy of an orbital depends on both n and l.

When solid lead (II) sulfide ore burns in oxygen gas, the products are solid lead (II) oxide and sulfur dioxide gas.? A. write the balanced equation B. how many grams of oxygen are required to react with 29.9 grams of lead II sulfide? C.