If you locate Argon (Ar) on the Periodic Table, you will see that it has an atomic weight 39.95 which is rounded up to 40 (hence Ar-40.) The number, 18, located at the top of Argon is it's atomic number which is a fancy way of saying "number of protons."
The atomic weight we were just talking about is the sum of the protons+neutrons. Since we are given the atomic weight and the atomic number (remember "number of protons"):
Atomic weight + Atomic number = Number of neutrons
39.95 18 22
Finding the number of electrons is the simplest part. In any atom (assuming that the atom's charge is balanced,) the number of electrons equals the number of protons. You will in most cases be assuming that the # of electrons equal the # of protons. Don't scare yourself and make it harder than it seems
Calcium has 20 protons and Chlorine has 17, so 20+17= 37 protons.
An atom's atomic number tells us how many protons it has. If we reference a periodic table, we see that calcium's atomic number is 20. Thus, calcium has 20 protons.
Calcium has 20 protons, 20 electrons and 20 neutrons in its most commonly found isotope.
Calcium (element number 20) has 20 protons and 20 electrons.
Atoms argon-40, potassium-40, and calcium-40 all have 40 protons, but differ in the number of neutrons in their nuclei. They are all stable isotopes, with no natural radioactivity.
40
20
An isotope of the element with 20 protons and 20 neutrons is calcium-40. Calcium has an atomic number of 20, which means it has 20 protons. The total number of protons and neutrons in calcium-40 is 40 (20 protons + 20 neutrons).
Calcium-40 has 20 neutrons. This is calculated by subtracting the atomic number (which is 20 for calcium) from the atomic mass of the isotope, which in this case is 40.
An atom of calcium has 20 protons, 20 neutrons, and 20 electrons.
The most common isotope of calcium is Calcium-40, which has 20 protons and 20 neutrons, totaling 40 nucleons.
The atomic number for calcium is 20, which means it has 20 protons in its nucleus. The mass number of calcium is 40, which is the total number of protons and neutrons in its nucleus.
The mass number of an atom is the sum of the protons and neutrons in its nucleus. Therefore, for an atom of calcium with 20 protons and 20 neutrons, the mass number would be 40.
The mass number of an atom of calcium with twenty protons and twenty neutrons is 40. This is because the mass number is the sum of the protons and neutrons in the nucleus of an atom.
Calcium has 20 Protons. You can determine the amount of Protons in an Element by checking the top number of an element. This is called the Atomic number. Calcium has 20 protons
Calcium has 20 protons and Chlorine has 17, so 20+17= 37 protons.
The element is calcium. It has an atomic number of 20, which corresponds to the number of protons. The sum of protons and neutrons gives the atomic mass number, which is 40 in this case.