Answer:
The answer to your question is molality = 0.34
Explanation:
Data
mass of NaBr = 14.57 g
mass of water = 415 g.
molality = ?
Process
1.- Calculate the molar mass of NaBr
NaBr = 23 + 80 = 103 g
2.- Calculate the moles of NaBr
103 g of NaBr ------------------ 1 mol
14.57 g of NaBr --------------- x
x = (14.57 x 1) / 103
x = 14.57 / 103
x = 0.141 moles
3.- Calculate the molality
molality = moles / volume
-Substitution
molality = 0.141 / .415
-Result
molality = 0.34
Explanation:
Alpha particles are less penetrating than a beta or gamma particle. Alpha particles are doubly charged helium nuclei. It consists of two neutrons and two protons.
The penetration of any ray is given by the following relation :
T = e^-u * L
Where
T is the transmittance of any material
u is the coefficient of penetration
L is the length of penetration
The mass and charge of alpha particle is more as compared to beta and gamma particles. They can produce ions easily. So, they penetrate more when compared to beta and gamma rays.
Answer:
See explanation
Explanation:
If the energy of the ground state E1 is known, then we need to measure the difference in energy between the energy levels E5 .and E1. We can obtain this by measuring the frequency or wavelength of a photon that is emitted when an electron moves from energy level E5 to E1.
From Bohr's model;
ΔE = E5 - E1
Hence;
E5 = ΔE + E1
Answer:
liquid, solid, and gas
Explanation: It depends where the molecules are moving. When a solid the molecules are vibrating and are all together, compact, the molecules are also very slow. When a liquid the molecules are moving back and forth, up and down, and are less compact, but moving faster. When a gas, the molecules move everywhere very quickly, moving super fast.
Answer:
There are a variety of methods by which a sample's boiling point can be determined, including distillation, reflux, and by using a Thiele tube. The most straightforward method uses a Thiele tube, and has the advantage of using less than 0.5mL of material.
Distillation Method
There are simpler methods than a distillation to measure a compound's boiling point, and it is recommended to explore other options (e.g. Thiele tube) if this is the only goal. However, if materials are limited, or if a purification is planned anyhow, a distillation can be used to determine a compound's boiling point. The distillation technique is discussed in great detail in Chapter 5.
A simple distillation should suffice for most situations and at least 5mL of sample should be used in the distilling flask along with a few boiling stones or stir bar. As the bulk of the material distills, the highest temperature noted on the thermometer corresponds to the boiling point. A major source of error with this method is recording too low a temperature, before hot vapors fully immerse the thermometer bulb. 5 Be sure to monitor the thermometer periodically, especially when the distillation is active. Record the barometric pressure along with the boiling point.
Reflux Method
A reflux setup can also be used to determine a compound's boiling point. Reflux is when a liquid is actively boiling and condensing, with the condensed liquid returning to the original flask. It is analogous to a distillation setup, with the main difference being the vertical placement of the condenser.
Thiele Tube Method