Question

23. On the periodic table, there are two numbers in the block for the element potassium, K: 19 and 39.098. What are the names of the numbers and what do they measure?

Answer 1

atomic number (19) measures how many protons it has
mass number (39.098) average of all the isotopes for potassium. as well as the number of protons + neutrons

Answer 2

Atomic number and atomic mass respectively.

Explanation:

• The number 19 means the atomic number of K. Atomic number is the number of electrons or protons in an atom.
• The number 39.098 indicates the atomic mass of the K.
• Atomic mass is the mass of an atom which is approximately equal to total number of protons and neutrons in the nucleus of K.