Answer:
Bubbles are comprised of gases, which have a lesser density than water. Since they are less dense, they get pushed up to the surface, and they rise, lighter than the liquid around them. This is just like helium in air; helium is lighter than air, so it rises, pushed to the top by the pressure around it.
PLS MARK THE BRAINLIST
Answer:
mass of Helium = mole of Helium x Molarmass of Helium
Explanation:
Mole of Helium = volume of Helium/ 22.4dm^3/mol
= 7.00 x 10^2/22.4
= 31.25mol
Mass of Helium = mole of Helium x Molarmass of Helium
= 31.25mol x 4g/mol
= 125g
Answer:
The volume of hydrogen gas produced at STP is 4.90 liters.
Explanation:

Moles of aluminium =
According to reaction , 2 moles of aluminium gives 3 moles of hydrogen gas.
Then 0.1333 moles of aluminium will give:
of hydrogen gas
Volume of 0.2 moles of hydrogen gas at STP = V
Temperature at STP = T = 298.15 K
Pressure at STP = P = 1 atm
n = 0.2 mol
PV = nRT (Ideal gas equation)

The volume of hydrogen gas produced at STP is 4.90 liters.
The answer is B, you just check if it is the same on the left and right side
A:
Left side - Right side
2xH - 2xH
1xS - 3xS
4xO - 12xO
2xAl - 2xAl
Therefore A is not correct
B:
Left side - right side
2xK - 2xK
1xCl - 1xCl
1xPb - 1xPb
2xN - 2xN
6xO - 6xO
B is therefore correct as both sides add up
Answer:
A. Ernest Rutherford
B.Bohr
C. Eugen Goldstein
D.. Santiago Ramon y cajal
E.john Dalton
F.isobars - a line drawn on a weather map connecting points of equal pressure is called isobars.
example.. argon 40
potassium 40
.two differences between isobars and isotopes.
isobars are those elements which have different atomic number but the same mass number. while isotopes are those elements having the same atomic number and different mass number..
two uses of isotopes.
uranium 235 - for nuclear fission and as fuel in unclear reactors.
# an isotope cobalt - used In the treatment for cancer
# an isotope iodine - used in treatment of goiter.