The equation you use here is
mass =moles x Mr
So:
Moles of K - 0.55mol
Mr of K - 39.1
Mass= 0.55x39.1 =21.505g
The scientist that performed the cathode ray experiment leading to the discovery of electrons is J.J. Thomson.
<h3>What is a cathode ray?</h3>
A cathode ray is a tube that contains negatively charged electrode( that is the cathode) which emits electrons when heated at a low pressure.
The cathode ray was used by the scientist, J.J. Thomson to find the ratio of charge to mass (e/m) of the electrons.
Therefore, the scientist that performed the cathode ray experiment leading to the discovery of electrons is J.J. Thomson.
Learn more about electrons here:
brainly.com/question/11316046
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Answer:
The value of the partial pressure of the oxygen
= 690 torr
Explanation:
Total pressure of the mixture of gases = 736 torr
The partial pressure of water vapor = 46 torr
From the law of pressure we know that
Total pressure = The partial pressure of water vapor + The partial pressure of oxygen 
Put the values of pressures in above equation we get,
⇒ 736 = 46 + 
⇒
= 736 - 46
⇒
= 690 torr
This is the value of the partial pressure of the oxygen.
<u>Answer:</u> The net ionic equation for the given reaction is 
<u>Explanation:</u>
Net ionic equation of any reaction does not include any spectator ions.
Spectator ions are the ions which do not get involved in a chemical equation. It is also defined as the ions that are found on both the sides of the chemical reaction when it is present in ionic form.
The chemical equation for the reaction of hydrochloric acid and potassium sulfite is given as:

Ionic form of the above equation follows:

As, potassium and chloride ions are present on both the sides of the reaction, thus, it will not be present in the net ionic equation.
The net ionic equation for the above reaction follows:

Hence, the net ionic equation for the given reaction is written above.
<u>Answer:</u> The correct option is d) 460 kJ
<u>Explanation:</u>
We are given:
Content of fat in energy drink = 2.0 g
Content of protein in energy drink = 6.0 g
Content of carbohydrate in energy drink = 16.3 g
Also,
The fuel value of fat = 38 kJ/g
The fuel value of protein = 17 kJ/g
The fuel value of carbohydrate = 17 kJ/g
So, the fuel value of the energy drink will be:
Total fuel value = 
Total fuel value = ![[76+102+277]=460kJ](https://tex.z-dn.net/?f=%5B76%2B102%2B277%5D%3D460kJ)
Hence, the correct option is d) 460 kJ