Which list contains all pure substance

What is the molar mass of sulfur hexafluoride gas if the density is 22.4g/L at STP?

The density of the unknown metal is 8.90 g/cm3. Use the information in the table to identify the unknown metal. Which substance is most likely the unknown metal?

What happens to the atomic size of the elements as one goes from the bottom to the top of a group? A) Atomic size stays the same as one moves from bottom to top in a group. B) Atomic size decreases as one moves from bottom to top in a group.

Calcium-47, used to evaluated bone metabolism, has a half-life of 4.5days: How many milligrams of a 16mg sample of calcium-47 remain after 18 days?

What could J. J. Thomson conclude from his experiments? A) Atoms are mostly empty space. B) Most of the mass of the atom is concentrated in the center. C) Atoms must balance positive and negative particles. D) Atoms are indivisible.

A gas in a rigid container is heated so that it's kelvin temperature doubles. What happens to its pressure

Common cause of biological contamination

Whcih kind if material would best accomplish this task

List at least two chemical reactions that resulted in a yellow, orange, or red precipitate. For these reactions, list the possible chemical name of the precipitate.

You place air in a sealed can at stp. ypu triple its absolute temperture (K) while leaveing the volume constant. what happenes to the pressure