Which of the following gases are typically used for colorful lighting when an electric current is applied?

A) hydrogen and helium

B) argon and krypton

C) fluorine and chlorine

D) oxygen and nitrogen

What is the vocab word for are first to grow in a new or disturbed area

Humans exhale carbon dioxide when they breathe. if the concentration of carbon dioxide in the air that people breathe gets too high, it can be fatal.

Which is an example of a chemical change? a pan of water boils. a candle burns. a teaspoon of salt dissolves. a burner gets red hot

in the fali, the relative humidity is high in early morning and as the temperature increases, the relative humidity decreases because (3 pts) A. saturation pressure of water increases B. water condenses C. water evaporates D.

What is the five part definition for an object to be considered a mineral

Why does the body of the bird covered with feathers?

One molecule of caffeine contains 8 atoms of carbon, 10 atoms of hydrogen, 2 atoms of oxygen, 4 atoms of nitrogen. write the formula for caffeine with the elements in the order they are given.

A piece of magnesium metal is heated in the presence of chlorine gas, and a reaction takes place. What compound will most likely be produced? A. Mg2C1 B. MgCl3 C. MgCl2 D. MgCI

What is the pressure of the gas in this mercury manometer if h = 81 mm and atmospheric pressure is 749 mmHg

A microscope containing two or more lenses is an