Which of these is a compound?

A. carbon

B. carbon dioxide

C. Air

D. oxygen

Using a 300 MHz NMR instrument: a. How many Hz downfield from TMS is a signal at 2.5 ppm? b. If a signal comes at 1200 Hz downfield from TMS, at what ppm does it occur? c. If two peaks are separated by 2 ppm, how many I-AZ does this correspond to?

Choose the correct statement (s) for the following reaction: 8Fe (s) + S8 (s) → 8 FeS (s) (a) Iron is being oxidized. (b) Iron is being reduced. (c) Sulfur is being oxidized. (d) Sulfur is being reduced

Explain how scientists might infer that a planet outside of our solar system might be capable of supporting life.

In 1687, ___ explained that gravitational forces hold the solar system together. A. Newton B. Copernicus C. Halley D. Galileo

Suppose you have two 100-mL graduated cylinders. In each cylinder there is 40.0mL of water. You also have two cubes: one is lead, and the other is aluminum. Each cube measures 3.0cm on each side.

You normally take 2 Ibuprofen (C13H18O2) when you have pain. Each one is 250 g. How many moles of ibuprofen do you take?

Atoms in a covalent bond are held together by what?

Draw the sulfur-containing product of the following oxidation reaction between two 2-methyl-1-propanethiol molecules. Draw all hydrogen atoms.

Describe the Earth's layers in relation to density

The first planet to be discovered using mathematical prediction was