The element with 4 protons in the nucleus in Beryllium.
Answer : The standard enthalpy of formation of ethylene is, 51.8 kJ/mole
Explanation :
According to Hess’s law of constant heat summation, the heat absorbed or evolved in a given chemical equation is the same whether the process occurs in one step or several steps.
According to this law, the chemical equation can be treated as ordinary algebraic expression and can be added or subtracted to yield the required equation. That means the enthalpy change of the overall reaction is the sum of the enthalpy changes of the intermediate reactions.
The formation reaction of 
will be,
The intermediate balanced chemical reaction will be,
(1) 
(2) 
(3) 
Now we will reverse the reaction 1, multiply reaction 2 and 3 by 2 then adding all the equations, we get :
(1) 
(2) 
(3) 
The expression for enthalpy of formation of will be,
Therefore, the standard enthalpy of formation of ethylene is, 51.8 kJ/mole
#1
The correct answer is A.)
Because the animal has sperm that means that the offspring will be different. This is because at conception, the two parents sex cells combine their DNA to make a new creature.
#2
The correct answer is B.)
Genetic variation produces different offspring, and some are more adapted to others. The ones that survive pass on their genes. This is know as "Survival of the Fittest". Asexually organisms are exactly like their parents, so if they have any type of genetic defaults, then their offspring will get them too.
Hope this helps!
<span />
Answer: Precision means that measurements are close to each other . Accuracy means that measurements are close to accepted value
Explanation:
Precision refers to the closeness of two or more measurements to each other.
For Example: If we weigh a given substance five times and you get 5.0 kg each time. Then the measurement is very precise.
Accuracy refers to the closeness of a measured value to a standard or known value.
For Example: If the mass of a substance is 5.0 kg and one person weighed 4.9 kg and another person weighed 3.9 kg. Then, the weight measured by first person is more accurate.
Thus Precision means that measurements are close to each other . Accuracy means that measurements are close to accepted value.
There's 6.022×10^23 particles in 1 mole of anything
like there is 1000 grams in 1 kilogram of anything
