What is the name of this hydrocarbon?
a. di-ethylbutane
b. di-ethylpropane
c. methylpropane
d. methylpropene
e. methylpropyne

What material does not melt at any temperature

Write the chemical formula for a compound that is made of an element from group 1 and an element from group 17

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 ?