An anion `M^(3-)` had 18 electrons , what is its atomic number ?

An atom of element E contains 3 protons, 3 electrons and 4 neutrons : (a) What is its atomic number ?

The atom of an element is made up of 4 protons, 5 neutrons and 4 electrons. What are its atomic number and mass number ?

The atom of an element is made up of 4 protons, 5 neutrons and 4 electrons. What are its atomic number and mass number?

An atom of element X contains 3 protons, 3 electrons and 4 neutrons: What is its atomic number?

An atom of an element has its K and L shells completely filled with electrons. What is its atomic number ?

The atom of an element X has 7 electrons in its M shell. What is the atomic number of element X ?

The mass number of an atom is 31. The M shell of this atom contains 5 electrons. What is the atomic number of this atom?

An element has 2 electrons in the M shell. What is the atomic number of the element ?

An element has 2 electrons in the M shell. What is the atomic number of the element ?

An atom has three shells. If there are 4 electröns in the third shell, then a) What is its atomic number? b) What is the number of protons? c) What is the number of electrons? d) Write the method of arrangement of the electron, in the shell?