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Who said atoms have different masses?
While all atoms of an element were identical, different elements had atoms of differing size and mass. Dalton’s atomic theory also stated that all compounds were composed of combinations of these atoms in defined ratios. Dalton also postulated that chemical reactions resulted in the rearrangement of the reacting atoms.
Who discovered different elements have different masses?
Dalton’s
Part two of Dalton’s theory had to be modified after mass spectrometry experiments demonstrated that atoms of the same element can have different masses because the number of neutrons can vary for different isotopes of the same element.
Who was the first scientist that stated atoms of different elements have different masses?
Dalton’s atomic theory proposed that all matter was composed of atoms, indivisible and indestructible building blocks. While all atoms of an element were identical, different elements had atoms of differing size and mass.
What indicates that an atom has no overall charge?
An atom contains equal numbers of protons and electrons . Since protons and electrons have equal and opposite charges, this means that atoms are have no overall electrical charge.
Who discovered the atom first?
Democritus
Democritus first introduced the idea of the atom almost 2500 years ago. Democritus was an important philosopher. However, he was less influential than the Greek philosopher Aristotle, who lived about 100 years after Democritus.
How did John Dalton come up with the atomic theory?
John Dalton. He imagined that all atoms were like small spheres, but they could have different properties. They varied in size, mass, or color. Dalton used this model to explan matter: -All matter is made up of small, indivisible particles called atoms. -All atoms of an element are identical in properties like size and mass.
Is the mass of an atom equal to its mass?
Yes. The nucleus of an atom consists of protons and neutrons. The mass of the protons plus the mass of the neutrons equals the mass of the atom (I simplified it a little bit, it’s not exactly the sum because of the so-called mass defect, but let’s keep it simple).
How are atoms of the same element different?
The atoms of a chemical element can exist in different types. These are called isotopes. They have the same number of protons (and electrons), but different numbers of neutrons. Because different isotopes have different numbers of neutrons, they do not all weigh the same or have the same mass.
Can an isotope of an element have the same atomic number?
Isotopes have the same atomic number but different mass number. Isotopes have very similar chemical properties but sometimes differ greatly in nuclear stability.” For example, carbon-12, carbon-13, and carbon-14 are three isotopes of the element carbon with mass numbers 12, 13, and 14, respectively.
https://www.youtube.com/watch?v=50t1D1rq6cs