Answer:
K₂CO₃
Explanation:
Given parameters:
Number of moles of K = 0.104mol
Number of moles of C = 0.052mol
Number of moles of O = 0.156mol
Method
From the given parameters, to calculate the empirical formula of the elements K, C and O, we reduce the given moles to the simplest fraction.
Empirical formula is the simplest formula of a compound and it differs from the molecular formula which is the actual formula of a compound.
- Divide the given moles through by the smallest which is C, 0.052mol.
- Then approximate values obtained to the nearest whole number of multiply by a factor to give a whole number ratio.
- This is the empirical formula
Solution
Elements K C O
Number of moles 0.104 0.052 0.156
Dividing by the
smallest 0.104/0.052 0.052/0.052 0.156/0.052
2 1 3
The empirical formula is K₂CO₃
An example of an allotrope is carbon:
Carbon can exist in graphite, diamond and amorphous
This problem is asking for the electron configuration of an excited atom of gallium, which according to the group it is, its excited state will theoretically be Ga³⁺, since it is a metal and loses three or less electrons, that is why it turns out positive. After writing the electron configuration, we realize the answer must be 2-8-17-4 according to the following:
<h3>Electron configurations:</h3><h3 />
In chemistry, electron configurations allow us arrange the electrons of an element according to specific energy levels and orbitals. In such a case, it turns out possible to write Gallium's electron configuration in its ground-state as follows:

However, since the given choices do not match with a charge of 3+ as formerly explained, we assume this gallium atom will be excited to 1+, due to the fact that the third energy level comprising 18 electrons, will give one to the fourth energy level, turning out in an electron configuration of:

Which matches with 2-8-17-4 as two electrons are present in the first energy level, eight in the second one, now seventeen in the third one and four in the fourth one.
Learn more about electron configurations: brainly.com/question/5524513
C.
This is because the number of products is greater than the number of reactants.
Answer: The statement collisions only result in a reaction if the particles collide with a certain maximum energy called the activation energy of the reaction, is false.
Explanation:
Activation energy is the minimum amount of energy required to initiate a chemical reaction.
So, when activation energy for a reaction is lower then molecules with lower energy can also participate in the reaction. As a result, more number of collisions will take place due to which an increase in the rate of reaction will takes place.
When activation energy for a reaction is larger then molecules with higher energy will not be able to participate in the reaction. As a result, less number of collisions will take place due to which a decrease in rate of reaction will occur.
Therefore, we can conclude that the statement collisions only result in a reaction if the particles collide with a certain maximum energy called the activation energy of the reaction, is false.