Which charged particle determines the atomic number of an element?
Proton present in nucleus
The atomic number (Z) of an element is defined as the number of protons in the nucleus of its atom.
Protons are positively charged and their number is fixed for every atom of a given element, so it identifies the element.
Outermost electrons decide valency, the mass of the atom relates to mass number, and neutrons are uncharged and can vary (isotopes), so none of these fixes the atomic number.
Hence, the answer is Proton present in nucleus.
Consider the following statements regarding Thomson's model of an atom.
Statement I: The atom is a sphere of positive charge with electrons scattered inside it.
Statement II: Thomson's model could explain the presence of the nucleus in an atom.
Which of the following is TRUE?
If an atom of magnesium loses a proton, what happens to its atomic number and identity?
Which element contains only one proton and one neutron among the following?
Which of the following best describes Thomson's model of an atom?
A new isotope has 20 protons, 22 neutrons, and 20 electrons. How does its mass number affect its chemical behavior compared to other isotopes of the same element?
Which of the following best describes why noble gases have a valency of zero?
An element has two isotopes with mass numbers 35 and 37. Which property remains the same in both isotopes?
Which description best represents Thomson’s atomic model?
Which subatomic particle carries a negative charge in an atom?
Which pair of atoms is an example of isotopes?
Which of the following electron transition in hydrogen atom will require largest amount of energy?
A species having 8 electrons in the third shell is very reactive while the other species having 8 electrons in the third shell is very inactive they are :
Which of the following is the general formula for saturated hydrocarbons?
Which one of the following is the average atomic mass of chlorine atom?