When stars are in the main sequence, what two forces act against each other to maintain a star's stable size?

The density of lead is 11.3 g/mL . The water level in a graduated cylinder initially at 206 mL rises to 287 mL after a piece of lead is submerged. What is the mass in grams of the lead?

Which statement about fusion is correct? A. Fusion is currently being used to generate electricity in power plants. B. Fusion occurs in the sun. C. Fusion occurs when neutrons split atoms. D. Fusion produces dangerous radioactive waste

The combustion of ethanol (CH3CH2OH, 46.1 g/mol) results in the formation of water and carbon dioxide. How many grams of carbon dioxide are produced when 46.1 g of ethanol burns?

Which of the following compounds is the most soluble in water? a) propanoic acid b) propane c) propanal d) l-bromopropane

A certain shade of blue has a frequency of 7.18 * 1014 Hz. What is the energy of exactly one photon of this light?

Choose the nonmetallic elements from the list. Check all that apply. A. yttrium B. oxygen C. boron D. polonium E. argon F. gallium G. carbon

How many grams of Tin (SN) would be required to use 6.9 moles of chlorine (cl2)

Identify the values that should be tested to see if a change occurs • x-values • y-values • h-values • z-values

The number of moles of cl - ions needed to combine completely with 0.25 moles of mg+2 ions is: 0.50 0.125 0.75 0.25

A change of state requires the addition or removal of heat energy.