how can the mass number be found
Count up the total number of ______ and __________ in the atom.
protons and neutrons
To find the mass number of an atom, you need to count the total number of protons and neutrons in the nucleus. Protons have a positive charge and neutrons have no charge.
To find the mass number of an atom, you need to count up the total number of protons and neutrons in the nucleus of the atom.
1. Determine the atomic number of the element: The atomic number represents the number of protons in the nucleus. It is usually displayed as a whole number above or before the element's symbol in the periodic table.
2. Identify the element's symbol: Each element in the periodic table is represented by a unique symbol (e.g., H for hydrogen, C for carbon, O for oxygen).
3. Look up the atomic mass of the element: The atomic mass of an element is usually displayed as a decimal number under or below the element's symbol in the periodic table. This value represents the average mass of all the isotopes of that element found naturally on Earth.
4. Calculate the mass number: The mass number is the sum of the number of protons and neutrons in the atom's nucleus. Since the atomic number already provides the number of protons, subtract the atomic number from the atomic mass to find the number of neutrons.
For example, let's say we are looking for the mass number of carbon (symbol: C). The atomic number of carbon is 6, which means it has 6 protons. The atomic mass of carbon is approximately 12.01. Subtracting the atomic number (6) from the atomic mass (12.01) gives us the number of neutrons, which is 6. The mass number of carbon is therefore 12 (6 protons + 6 neutrons).
So, to summarize, you can find the mass number by counting up the total number of protons and neutrons in the nucleus of the atom.