Answer:
The correct answer is 25 mL graduated cylinder (it should be used in all the cases)
Explanation:
In order to measure 25.00 ml sample of a solution it should be used a 25 mL graduated cylinder, as it is previously and properly calibrated. The other laboratory glassware, beaker and erlenmeyer, have graduations which are approximate, so they are used when exact volumes are not needed.
ii) graduated cylinder has the least uncertainly. It is more accurate than a beaker or erlenmeyer (to within 1%)
iii) A 25 mL graduated cylinder should be used because it is the most accurate lab glassware (between those were mentioned: beaker, erlenmeyer).
what is that i cant see anything?
Answer:
The density of the ideal gas is directly proportional to its molar mass.
Explanation:
Density is a scalar quantity that is denoted by the symbol ρ (rho). It is defined as the ratio of the mass (m) of the given sample and the total volume (V) of the sample.
......equation (1)
According to the ideal gas law for ideal gas:
......equation (2)
Here, V is the volume of gas, P is the pressure of gas, T is the absolute temperature, R is Gas constant and n is the number of moles of gas
As we know,
The number of moles: 
where m is the given mass of gas and M is the molar mass of the gas
So equation (2) can be written as:

⇒ 
⇒
......equation (3)
Now from equation (1) and (3), we get
⇒ Density of an ideal gas:
⇒ <em>Density of an ideal gas: ρ ∝ molar mass of gas: M</em>
<u>Therefore, the density of the ideal gas is directly proportional to its molar mass. </u>
Yes. Mercury has 80 protons. Tin has 50 protons. Same for electrons, it just doesn't have an exact number.