22. Manganese is element 25 in the periodic table with a mass number of 55.
How many neutrons are there in an atom?
A. 5
C. 20
B. 10
D. 30
23. Selenium has 34 protons and 45 neutrons. What is the Mass Number?
A. 75
C. 79
B. 85
D. 109
24. Where does the mass of an atom is most probably concentrated?
A. Inside the nucleus
B. Outside the nucleus
C. Neither inside of A & B
D. Cannot be determined
25. Why atomic number is unique?
A. The atomic number is can be shared.
B. The atomic number gives identity to every atom.
C. The atomic number is equal to the number of protons.
D. The atomic number is equal to the number of electrons
26. The neutral Fluorine atom has 9 protons. What is the number of its electrons?
A. 9
B. 19
C. 28
D. 10
27. What do you call to the difference between the mass number and the atomic
number?
A. Nucleons
B. Mass Number
C. Number of Neutrons
D. Atomic Number
or of