Answer:
D. -120.9 kJ
Explanation:
According to Hess's law ,the total enthalpy change for a reaction is the sum of all changes regardless of the stages or the steps of the reaction.
....(1)
(this reaction should be reversed in order to reach the required reaction )
On reversing the reaction the sign of get reversed.
(In this case change sign from '-' to'+'. Hence = + 65 kJ)
....(1)
......(2)
Adding equation (1) and (2)
(It is nearly equal to -120.9 kJ)
Answer:
Proton = 119
Electron = 119
Neutron = 183
Explanation:
Mass number (A) = 302
Atomic number (Z) = 119
Proton = atomic number = 119
Since there is no charge on the element, it means the element is neutral.
Therefore,
Electron = proton = 119
Mass number = proton + Neutron
Neutron = Mass number — proton
Neutron = 302 — 119
Neutron = 183
Answer:
The statement which describes an intensive property of matter is - :
<u>it is the same for every sample of a single substance.</u>
Explanation:
- <u>It is the same for every sample of a single substance. -:</u> Since a substance 's intense property does not depend on either mass or volume, it is the same for each sample of a single substance. <u>Hence , this statement is correct .</u>
- <u>It depends on how a substance was formed -:</u> Intensive property do not depend upon the amount of the substance or the formation of the sample . <u>Therefore this statement ifs wrong about intensive property .</u>
- <u>It is the same for every sample of every substances -: </u> This is not possible to be for every sample of the substance , a every substance have different qualities. <u>Hence this statement is also incorrect.</u>
- <u>it depends on the amount of substances present -: </u> This is the characteristic of a extensive property of matter that relies on the amount of the material/substance.<u> This assertion is, therefore, not valid.</u>
Hence ,<u> the correct option is A (it is the same for every sample of a single substance).</u>
Answer:
Anion is negatively charged particle.
Calcium +2. Its cation
Oxygen -2
Explanation:
An anion is a charged particle with a negative charge. Anions has charge of -1
Oxygen require two electrons to complete its octet and hence its charge is -2
Calcium is a cation and has a positive charge of +2