Answer:
See below.
Explanation:
Because copper is a very good conductor of electricity so it will likely conduct any electricity away from the person.
Answer:
c.
Explanation:
A serial dilution is a dilution that is made fractionated. The stock solution is diluted, then this now solution is diluted, and then successively. The final dilution is the multiplication of the steps dilutions.
The representation of the dilution is v/v (volume per volume) indicates how much of the stock solution is in the total volume of the solution. So 1/5 indicates 1 mL to 5 mL of the solution. If the final volume must be 1 mL, then the stock solution must be 0.2 mL (0.2/1 = 1/5), and the volume of the solvent is 1 mL - 0.2 = 0.8 mL.
The second solution is done with a dilution of 1/10 or 1 mL of the first solution in 10 mL of the total solution. Because the solution has 1 mL, then the volume of the first solution must be 0.1 mL (0.1/1 = 1/10), and the volume of the solvent that must be added is 1 mL - 0.1 mL = 0.9 mL.
Which type of telescope is most useful for detecting a star that emits very long electromagnetic waves?
A. a radio telescope B. an X-ray telescope C. an optical telescope D. a gamma ray telescope
A.)a radio telescope
Answer:
Higher boiling point and lower freezing point
Explanation:
Boiling point is the temperature at which substances goes to gaseous phase form their liquid phase. Liquids boil when vapour pressure of the liquid becomes equal to atmospheric pressure. So boiling point of a liquid is affected by the change in its vapour pressure and vapour pressure is affected by adding a non-volatile solute in it.
Effect of adding non -volatile solute on vapour pressure:
When a non-volatile solute is added to a liquid, it alters the interaction between the liquid particles and prevents the liquid particles to going into gaseous phase which results in decrease in vapour pressure. More energy is needed for the vapour pressure of the liquid to becomes equal to atmospheric pressure. Therefore, boiling point increases.
CaCl2 is a non-volatile solute and hence increases the boiling point of the water.
Effect of adding non-volatile solute on freezing point:
When a non-volatile solute is added to a liquid, it alters the interaction between the liquid molecules. The new solute and solvent interaction prevents the liquid to soldify and requires more lowering in temperature. Therefore, freezing point decreases.
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.
