The noble gases are the least of any elements on the periodic table.

The
form acidic compounds with hydrogen.

The halogens are the most reactive among all the
.

What reaction is taking place? 02 + c3h8 = h20 + co2

Nebulae are enormous clouds in outer space. they are made mostly of hydrogen gas, helium gas, and dust. some nebulae glow brightly, while others do not. the stars that people see are huge, bright balls of glowing gas. they are made mostly of hydrogen and helium. which statement correctly describes other ways in which nebulae and stars are different? a. stars can form inside a nebula but a nebula can never be produced by any star. b. a star always has a higher density than a nebula. c. stars can never form inside a nebula but a nebula can be produced by any star. d. a nebula always has a higher density than a star.

Explain in detail of the four major scientific developments that spurred the formulation of the plate tectonics theory