What observation led Marie Curie to discover radium and polonium?

Magnesium is a light metal with a density of 1.74 g/cm3. What volume is occupied by 1.35 kg of magnesium?

Conditions for an experimental chemistry reaction require a temperature of 300 K. The temperature in the lab is 55 F. Which of the following must you do to meet the requirements?

What is the mass of 6.8 moles of C2H2O? Round your answer to two decimal places.

What is the correct name for Hg (NO3) 2? Mercury (I) nitrate Mercury (II) nitrate Mercury nitroxide Mercury dinitride

If all of the bonding electrons in a molecule are bonded in two hybrid sp orbitals, which shape does the molecule most likely have? linear tetrahedral trigonal planar trigonal pyramidal

How can a neutral atom become a positively-charged particle?

The last column of the periodic table contains the noble gases, elements that do not easily form chemical bonds.

When pollution is removed from the air by a natural process, it

What atomic property is different in each isotope of an element?

How do carbon-12 and carbon-13 differ? Select all that apply. They have different amounts of neutrons. They have different atomic charges. They have different mass numbers. They have different amounts of electrons.