An atom has two valence electrons, but four shells. This element is a member of which group or family? A. halogen
B. noble gas
C. alkaline earth metal
D. alkali metal

The table describes how some substances were formed substance 19 description formed by boiling pure water formed by combining three hydrogen atoms to every nitrogen atom formed by adding 5 g of sugar to 1 l of water formed by compressing carbon under high pressure based on the given descriptions, which substance is most likely a mixture?

Large helium-filled balloons are used to lift scientific equipment to high altitudes. what is the pressure inside such a balloon if it starts out at sea level with a temperature of 10.0ºc and rises to an altitude where its volume is twenty times the original volume and its temperature is – 50.0ºc ?

To find the enthalpy of a reaction in the lab, you measured the of the reactants and the change during the reaction.