The answer is "C" because all isotopes have a different mass number. The number of protons does not change. The mass of electrons is negligible. Thus, the number of neutrons changes.
Answer : The concentration of solution is, 8.53 M.
Explanation :
As we are given, 45.0 mass % solution of ethanol in water that means 45.0 g of ethanol present in 100 g of solution.
First we have to calculate the volume of solution.
Now we have to calculate the molarity of solution.
Mass of = 45.0 g
Volume of solution = 114.5 mL
Molar mass of = 46.07 g/mole
Molarity : It is defined as the number of moles of solute present in one liter of volume of solution.
Formula used :
Now put all the given values in this formula, we get:
Therefore, the concentration of solution is, 8.53 M.
Answer:
Final state of the hydrogen atom is the state where principle quantum number n = 2
Explanation:
When a photon of light having wavelength of 93·73 nm falls on hydrogen atom, the atom absorbs an energy of (h×c)÷93·73 nm
as Energy E = (h×c)÷wavelength
where
h is the Planck's constant
c is the speed of light in vaccum which is 3× m/s
Energy that is released is (h×c)÷410·1 nm
Let the principle quantum number of the final state of the hydrogen atom be n
According to the Bohr's principle
Energy difference between two states = ΔE = ( (1÷n²) - 1)
as the principle quantum number of the final state is n and principle quantum number of the initial state is 1
∴ ΔE = (h×c)((1÷93·73 nm) - (1÷410·1 nm))
( (1÷n²) - 1) = (h×c)((1÷93·73 nm) - (1÷410·1 nm))
( ( (1÷n²) - 1)) ÷ (h×c) = (1÷93·73 nm) - (1÷410·1 nm)
∴ n≈2
∴ Principle quantum number of the final state is 2
Answer:
The substance has a specific heat of 1.176 J/g°C
Explanation:
<u>Step 1: </u>Data given
Temperature change = 34 °C
Mass of the substance = 20 kg = 20000 grams
The substance gained 800 kJ of heat during this temperature change
<u>Step 2:</u> Calculate the specific heat
q = m*c*ΔT
⇒ with q = heat gained = 800 kJ = 800000 J
⇒ with m = the mass of the substance = 20 kg = 20000 grams
⇒ with c = the specific heat of the substance = TO BE DETERMINED
⇒ with ΔT = the change of temperature = T2 -T1 = 48° - 14 ° = 34°
c = q/(m*ΔT)
c = 800000 / (20000 * 34)
c = 1.176 J/g°C
The substance has a specific heat of 1.176 J/g°C
Answer:
Explanation:
Intermolecular forces are the forces that hold the molecules together in a substance. The state in which this substance will be at normal atmospheric conditions, and other physical properties such as boiling and melting points, are a consequence of the intermolecular forces.
The type of intermolecular force that happens in nonpolar compounds is dispersion forces. The atom or nonpolar molecule will be disturbed by the proximity of an ion or a polar molecule, thus shifting its electron cloud. The atom or nonpolar molecule will be an induced dipole.
In these tetrahedral molecules, which are not polar, the attractive forces will be London forces, which arise as a consequence of temporary induced dipoles.
Since these forces depend on proximity (the closer the proximity the larger the attraction) <u>those molecules with a higher molar mass will have a larger electron cloud, which will be more susceptible to the effect of an induced dipole in the surroundings</u> (the electrons are on the outer layers will be less attracted by the nuclei).
CF₄ > CCl₄ > CBr₄ >Cl₄
--------------------------------> Increasing size
--------------------------------> Increasing melting point
The melting point increases as the molecules get bigger, that is, as the number of molecules in the molecule increases.