Calcium-40: The atomic number of calcium is 20 and the number of neutrons is always the difference between the Atomic Mass and the atomic number.
Potassium I reckon
Calcium
The element with 22 protons is titanium (Ti). The sum of protons and neutrons determines the isotope, so with 26 neutrons, the isotope is titanium-48 (22 protons + 26 neutrons = Ti-48).
An element with 40 nucleons has a mass number of 40, which can correspond to several isotopes. The most common element with 40 nucleons is calcium (Ca), which has an atomic number of 20 and typically consists of 20 protons and 20 neutrons. However, other isotopes with 20 protons and varying numbers of neutrons could also have a mass number of 40.
Calcium is an element, which means that it is made up protons/electrons and neutrons. Each calcium atom contains a total of 20 protons/electrons, and 20 neutrons.
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 is the answer. Atomic weight 40 - with 20 protons means 20 neutrons. Calcium is a key element in teeth and bones.
Several can. Perhaps you meant to ask which has 20 protons, in which case the answer is calcium. (Calcium is also one of the elements that can have 20 neutrons, but it's not the only one.)
1) it's spelt Calcium and 2) 20 protons, 20 electrons, 20 neutrons
Argon-20
This element is calcium.
Calcium: The identity of an element is determined by how many protons each atom of the element has, and calcium is the name of the element with 20 protons per atom.
Potassium I reckon
You are calcium. Most calcium atoms have 20 neutrons though 20 - 28 is possible, but it is the fact that they have 20 protons which makes them calcium.
The element with 20 protons, 20 neutrons, and 18 electrons is calcium. Calcium has an atomic number of 20, which tells us the number of protons in the nucleus. The number of protons and electrons should be equal for a neutral atom, therefore in this case the element is calcium.
The number of neutrons in an atom can be calculated by subtracting the atomic number (number of protons) from the atomic mass. For calcium with an atomic number of 20, if the atomic mass is 40, then the number of neutrons would be 40 - 20 = 20 neutrons.
The type of element of a particular atom is based solely on its number of protons. An atom with 9 protons has an atomic number of 9, and is (looking on the elemental chart...) fluorine (F).