But remember, there are no electrons inside the nucleus. This is the chemical symbol for chlorine, written with its mass number and atomic number. Calculate the number of protons, neutrons and ...

which is based on atomic number rather than atomic mass. This arrangement was established by the British physicist Henry Moseley in 1913, who discovered that the atomic number (the number of ...

For example, a helium atom has an atomic mass of 4, but an atomic number (or positive charge) of 2. Since electrons have almost no mass, it seemed that something besides the protons in the nucleus ...

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Photo: Niels Bohr's research notes for his new atomic theory Rutherford's find came ... Rutherford deduced that the atom must have nearly all its mass, and positive charge, in a central nucleus ...

There are no CO 2 or other harmful atmospheric emissions from the ... Fission splits a heavy element (with a high atomic mass number) into fragments; while fusion joins two light elements (with a low ...