Answer:
A is the correct answer.
Explanation:
An atom consist of electron, protons and neutrons. Protons and neutrons are present with in nucleus while the electrons are present out side the nucleus.
All these three subatomic particles construct an atom. A neutral atom have equal number of proton and electron. In other words we can say that negative and positive charges are equal in magnitude and cancel the each other. For example if neutral atom has 6 protons than it must have 6 electrons. The sum of neutrons and protons is the mass number of an atom while the number of protons are number of electrons is the atomic number of an atom.
For example in case of Helium:
The 1st one diagram shows that arrow is pointing with in nucleus. The helium nucleus contain two protons and two neutrons. Thus maximum mass is present with in nucleus. while two electrons are revolve around the nucleus and mass of electron is negligible.
Answer:
Magnesium carbonate doesn't dissolve in water, only acid, where it will effervesce (bubble).
Explanation:
An insoluble metal carbonate reacts with a dilute acid to form a soluble salt. Magnesium carbonate, a white solid, and dilute sulfuric acid react to produce magnesium sulfate. Colourless magnesium sulfate heptahydrate crystals are obtained from this solution.
Answer:
Procedure (2)
Explanation:
Assume the dialyses come to equilibrium in the allotted times.
Procedure (1)
If you are dialyzing 5 mL of sample against 4 L of water, the concentration of NaCl will be decreased by a factor of
Procedure (2)
For the first dialysis, the factor is
After a second dialysis, the original concentration of NaCl will be reduced by a factor of
Procedure (2) is more efficient by a factor of
Answer:
Hydrogen has the highest rate of effusion
The freezing temperature at a normal sea level air pressure is negative 78.5 degrees.
