(2) subtracting the atomic number from the atomic mass number, because the mass number is the total number of protons and neutrons in an atom and the atomic number is the number of protons in an atom.
There are four sodium atoms in the product.
A reaction equation is said to be balanced when the number of atoms of reactants are equal to the number of atoms of products according to the balanced reaction equation.
Given the reaction between sodium metal and oxygen, the reaction could be written as; 2Na(s) + O2(g) ----> 2Na2O(s). We can see that there are four sodium atoms in the product.
Learn more about balancing reaction equations: brainly.com/question/2510547
Answer: Water, tin, sulfur, sucrose, salt, and etc.
Explanation: The photo has more examples
One half of the distance between the nuclei of two atoms bonded together by a single bond is known as the covalent bond radius. When a covalent bond is present between atoms, this radius can be determined. It is the radius of the two atoms because they are equally attracted.
Answer : The enthalpy of this reaction is, 0.975 kJ/mol
Explanation :
First we have to calculate the heat produced.
where,
q = heat produced = ?
m = mass of solution = 126 g
c = specific heat capacity of water = 
= initial temperature = 
= final temperature = 
Now put all the given values in the above formula, we get:
Now we have to calculate the enthalpy of this reaction.
where,
= enthalpy change = ?
q = heat released = 1.95 kJ
n = moles of compound = 2.00 mol
Now put all the given values in the above formula, we get:
Thus, the enthalpy of this reaction is, 0.975 kJ/mol
