Answer:
Explanation:
R = Rydberg constant = 
= Principal quantum number of an energy level = 2
= Principal quantum number of an energy level for the atomic electron transition = 4
Wavelength is given by the Rydberg formula
The wavelength of the light emitted is .
The heat from your hand would be absorbed by the (assumed) colder flask, since an endothermic reaction means that the reaction requires an absorption of heat as opposed to an exothermic reaction, which releases heat.
Answer:
The molecular weight for the compound is 60.1 g/mol
Explanation:
We need to determine the molality of solute to find out the molar mass of it.
We apply the colligative property of freezing point depression:
ΔT = Kf . m . i
If the compound was also found to be nonvolatile and a non-electrolyte,
i = 1.
Freezing T° of pure solvent - Freezing T° of solution = Kf . m
0°C - (-2.05°C) = 1.86°C/m . m
2.05°C / 1.86m/°C = m → 1.10 mol/kg
To determine the moles of solute we used, we can multiply molality by the mass of solvent in kg → 202.1 g . 1kg/1000g = 0.2021 kg
1.10 mol/kg . 0.2021kg = 0.223 moles
Molar mass→ g/mol → 13.39 g / 0.223 mol = 60.1 g/mol
Answer:
True
Explanation:
The oil drop experiment was carried out by Robert Millikan and Harvey Fletcher in 1909 to determine the charge of an electron. By balancing downward gravitation force with upward drag and electric force, they suspended small charged droplets of oil between two metal electrodes.
The charge over an oil droplet was often an integral value of e, was determined by changing the intensity of the electric field.
So, the given statement is true
Answer:
A magnet ( Magnetic attraction ) is used to separate the solid mixture that contain magnetic substances such as mixture of sand and iron fillings . Filtration process is used to separate solid materials that are insoluble in water such as mixture of sand ( or mud ) and water.
Explanation:
