Asteel container with a movable piston contains 2.00 g of helium which was held at a constant temperature of 25 °c. additional helium was pumped into the container and the piston adjusted so that the gas pressure remained constant. how many grams of helium were added to the cylinder if the volume was changed from 2.00 l to 3.00 l? a) 0.700 gb) 2.00 gc) 1.8 gd) 1.00 ge) 9.7 gf) 5.63 gg) 4.63 g

D) 1.00 g

Explanation:

According to the Avogadro's law, the volume of gas is directly proportional to the number of moles of gas at same pressure and temperature. That means,

or,

where,

= initial volume of gas  = 2.00 L

= final volume of gas = 3.00 L

= initial moles of gas  =

= final moles of gas  = ?

Now we put all the given values in this formula, we get

Mass of helium =

Thus mass of helium added = (3.00-2.00) g = 1.00 g

it is to be noted that an alpha particle is an helium nucleus. so it contains 2 protons 2 neutrons and has a mass number of 4. when alpha decay particles are ejected from the nucleus it gets transformed into an atom which has atomic number less than 2 and a mass number less than 4.

an equation that could represent alpha decay is radium 226 decay of alpha particle forms radon 222.

→

the number of protons in the nucleus of a given element. has slight luster and conducts electricity at high temperatures like metal.but like a nonmetal,boron is brittle and does not conduct electricity well at low temperatures. in graphite, carbon is a soft,brittle solid.it is reflective,ductile,or malleable.