Answer : The molecular weight of a substance is 157.3 g/mol
Explanation :
As we are given that 7 % by weight that means 7 grams of solute present in 100 grams of solution.
Mass of solute = 7 g
Mass of solution = 100 g
Mass of solvent = 100 - 7 = 93 g
Formula used :
where,
= change in freezing point
= temperature of pure water = 
= temperature of solution = 
= freezing point constant of water = 
m = molality
Now put all the given values in this formula, we get
Therefore, the molecular weight of a substance is 157.3 g/mol
False, gravity is a force, matter has mass and volume.
Na2C03 is formed through the reaction of
NaOH and H2CO3 namely sodium hydroxide and carbonic acid
NaOH -> strong base
H2CO3-> weak acid
Answer:
a, b, c, d
Explanation:
Rutherford’ atomic model is based on the gold foil experiment. In this experiment, beam of alpha rays was bombarded on thin gold foil. He observed that:
Most of the alpha particles passed through thin foil without any deflection.
Few alpha particles deflected by an angle of 90o.
Based on observation, Rutherford concluded that majority of the space inside the atom is empty.
He explained defection of few alpha particles by assuming that most of the mass is concentrated at the nucleus and positively charged.
Therefore, among given, the correct statements are:
The atom contains a positively charged nucleus.
Positive charge is condensed in one location within the atom.
The majority of the space inside the atom is empty space
The mass of an atom is concentrated at the nucleus
Therefore, the correct options are:
a, b, c, d
Answer:
When you eat food, your body can use the chemical energy in the food to make your muscles move so you can breathe, walk, run, jump, lift things, and do all the other things you need to do to live. The chemical energy in the food gets changed into the mechanical energy of moving muscles.
