Atomic number (Z) of tungsten is 74
Mass number (A) of tungsten is 184
Now:
Atomic number of an element = Number of protons = Number of electrons
Mass number = Number of Protons + Number of neutrons
In the case of tungsten
Total Number of electrons = 74
Jeffrey has already added 21 electrons
Number of electrons needed = 74 - 21 = 53
Ans (D) 53 more electrons are needed to complete the neutral atom of tungsten.
<u>Ans: 650 J = 155 calories</u>
<u>Given:</u>
Energy in joules = 650 J
<u>To determine:</u>
The energy in calories
<u>Explanation:</u>
1 joule = 0.2388 calories
Therefore, 650 joules = 0.2388 calories * 650 J/1 J = 155 calories
Explanation:
It is known that 1 gram contains 1000 milligrams. And, mathematically we can represent it as follows.
or 
So, when we have to convert grams into milligrams then we simply multiply the digit with 1000. And, if we have to convert a digit from milligrams to grams then we simply divide it by 1000.
If the mass of both the reactants is 10kg then the mass of the products also equals 10kg.
It is due to the law of conservation of mass.
Mass can neither be created nor be destroyed.
