Answer:
The answer to your question is given below.
Explanation:
Data obtained from the question include:
Sodium, Na => 1s2 2s2 2p6 3s1
Magnesium, Mg => 1s2 2s2 2p6 3s2
Aluminium, Al => 1s2 2s2 2p6 3s2 3p1
Sodium has 1 valence electron. If we remove the valence electron, sodium metal will become an ion. Thus, the electronic configuration becomes
1s2 2s2 2p6.
Magnesium has 2 valence electrons. If we remove the valence electrons, magnesium metal will be an ion. Thus, the electronic configuration becomes
1s2 2s2 2p6.
Aluminium has 3 valence electrons. If we remove the valence electrons, aluminum metal will become an ion. Thus, the electronic configuration becomes
1s2 2s2 2p6.
Isotopes are atoms with different number of electrons
isotopes are very useful
for example isotope of uranium is used in atomic bombs and nuclear reactors radioactive isotopes are used to date ricks soils and archaeological objects.
isotopes have many uses that's why we study isotopes to know their uses
Answer : The vapor pressure of water at is 1.01 atm.
Explanation :
Boyle's Law : It is defined as the pressure of the gas is inversely proportional to the volume of the gas at constant temperature and number of moles.
or,
where,
= initial pressure = ?
= final pressure = 750 torr = 0.987 atm (1 atm = 760 torr)
= initial volume = 1.95 L
= final volume = 2.00 L
Now put all the given values in the above equation, we get:
Therefore, the vapor pressure of water at is 1.01 atm.
Given parameters:
Weight of hydrated sample = 20g
Temperature = 250°C
Weight after cooling = 16.5g
Unknown:
Weight of water lost from the sample = ?
Solution:
The weight of water lost from the sample;
Weight of water lost = Weight of hydrated sample - Weight of dry sample
Weight of water lost = 20g - 16.5g = 3.5g
% of water in the sample =
Input parameters solve;
=
=17.5%
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