Chemistrymedium · Past Paper
An atom has 7 protons and 8 neutrons. What is its mass number?
A7
B8
C15
D56
✓ Correct Answer: C — 15
Mass number = protons + neutrons = 7 + 8 = 15.
Share this question
More from Chemistry
- A neutral atom of an element has 2, 8, 8, 1 configuration. How many neutrons are in its isotope with mass 40?
- What is the effect of increasing the concentration of $H^+$ ions on pH?
- How many liters of Oxygen are needed to completely react with 22.4L of Hydrogen to form water vapor at STP?
- In the modern periodic table, where are the non-metals located?
- Which of the following elements is a noble gas?