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Why do atoms of the same element always have the same atomic number but have different mass numbers?
Wiki User
∙ 13y ago
An isotope is an atom that has different numbers of neutrons compared to its protons. So each variation of neutron numbers will give it a different mass number, but will still retain its atomic number.
Wiki User
∙ 15y ago
Wiki User
∙ 15y agoThe atomic number of an element refers to the number of protons in its nucleus, and this number never varies - an atom with a different number of protons is a differentelement. But, the number of neutrons in an atom of the same element can vary. An atom of the same element with a different number of neutrons is called an isotope. In isotopes, the mass number refers to the number of protons plus the number of neutrons in the nucleus of the atom. mass number = atomic number + number of neutrons For example, chlorine (Cl) has 17 protons, so its atomic number is 17. But there are isotopes of chlorine that can have either 18 or 20 neutrons, each giving chlorine a different mass number. So the two isotopes of chlorine are: 17 + 18 = mass number 35 17 + 20 = mass number 37 [Note: There are a number of other isotopes of chlorine, but these common ones are cited for examples.]
Wiki User
∙ 15y agoThe mass of an atom is almost all in the nucleus of the atom; this is the small positively charged bit in the middle that the electrons buzz around. When we talk about the mass of an atom it is the nucleus we are interested in. The nucleus of an atom is made up of protons and neutrons. Protons are the positively charged particles in the nucleus and they are what decide what the atom is. Hydrogen has 1 proton, helium has 2 protons, lithium has 3, iron has 26, gold has 79 and so on. If it has 1 proton it is hydrogen, if it has 79 protons it is gold. Each element has its own unique number of protons. Unfortunately its not quite that simple, if there were only protons in the nucleus then hydrogen would have an Atomic Mass of 1, helium 2, gold 79, etc. but there are neutrons as well. This means the weights don't go up by 1 each time, it depends how many neutrons the element tends to have but the weight does keep going up as you move through the table.
Wiki User
∙ 13y agoIt happens for most elements that you can get one or two or more extra/fewer neutrons in the nucleus. These are uncharged so the proton/electron counts are identical, and they are chemically practically identical. Called "isotopes".
Wiki User
∙ 13y agoThe atomic number of an element tells you how many protons an atom has in it's nucleus, and each element is defined by the number of protons it has. For example hydrogen always has 1 proton.
The Mass number tells you how many protons and neutrons there are in an atom. However it is possible for an element to have different numbers of neutrons in the nucleus. When this occurs you will get different masses for the same element but the same atomic number.
Two (or more) elements are known as isotopes if the only difference between them is the number of neutrons.
Probably the most common/well known example of an isotope is Hydrogen, Deuterium (Hydrogen with a neutron) and Tritium (Hydrogen with 2 neutrons)
Wiki User
∙ 13y ago"Same element" means the nucleus has the same number of protons, and that defines the element. But the number of neutrons in the nucleus can differ from one atom to another within nuclei of a given element. These atoms with "variant" nuclei are called isotopes of the element, with the mass number being the sum of protons and neutrons in the nucleus. (A neutron has mass almost the same as the mass of a proton).
Wiki User
∙ 12y agoDifferent isotopes of the same element have different masses, due to them having different amounts of neutrons.
For example, the most common isotope of Hydrogen, protium, has one Proton and one Neutron, giving it a mass number of 1. Another isotope of Hydrogen, tritium, has one Proton and three neutrons, giving it a mass number of 4.
Wiki User
∙ 8y agoDifferent isotopes have different numbers of neutrons so their mass numbers are different.
Wiki User
∙ 12y agoThe number of neutrons can vary for an element, creating atoms of different weights which are known as isotopes.
Wiki User
∙ 13y agoThere are isotopes of the same element and therefore have different masses due to a different number of neutrons.
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Which is the average of the mass numbers of an element's isotopes?
the Atomic Mass
Do isotopes of the same element have different atomic numbers?
NO. An element always has its own unique atomic number, because the atoms of that element all have identical amounts of protons. Counting the number of protons in a nucleus of an atom reveals the identity of the atom. So, all atoms of the same element have the same atomic number.However atoms of one element CAN have a different masscaused by different number of neutrons in nucleus: these are called isotopes of that element.No. The only thing that can change within an given element, is the atomic mass usually referred to as isotopes, which means there is a different abundance of each isotope.For example chlorine has two isotopes one which is 75.78% and a atomic mass of 34.969 and the second is 24.22% and a atomic mass of 36.966.Now calculate the average atomic mass and you have a answer of 35.45.
Do Isotopes of uranium have different atomic numbers?
No. By definition isotopes of an element have the same number of protons (that is what makes them uranium, for example) but different numbers of neutrons (neutral particules in the nucleus which provide mass).
What is a similarity and a difference between isotopes of an element?
All isotopes of an element have the same number of protons in the atomic nucleus, which is its atomic number on the periodic table. All isotopes of an element contain different numbers of neutrons in their atomic nuclei, which causes the isotopes of an element to vary in mass number (protons + neutrons).
How are the isotopes of an element are alike and how are they different?
The isotopes of an element are alike in that they have the same number of protons, electrons, and the same chemical properties. The isotopes are different in that they have different numbers of neutrons and thus different atomic masses.
Does an isotope of an element have a different atomic mass?
Yes; isotopes of the same element have the same atomic number but differ in their atomic masses.
Do isotopes of an element have the same atomic mass but different atomic number?
The different mass numbers are due to different numbers of neutrons.
Why are the atomic mass numbers of an element not hole numbers?
Its the average of the weight of the different isotopes of that element.
Form of an element having different atomic and number of neutrons?
Isotopes have different numbers of electrons, but not different atomic numbers (numbers of protons) or they'd be different elements.
How can different atoms of the same element have the same atomic number but can have different mass numbers?
They have different numbers of neutrons.
What element has the atomic number for 3.14?
No element has this atomic number. All atomic numbers are whole numbers.
Do some atoms have more or fewer protons than will other atoms of the same element?
No. The atomic number of an element is determined by its number of protons. If two atoms have different numbers of protons, they have different atomic numbers and are different elements.
Can two atoms of same element ever have different atomic numbers?
The atomic number is identical for all the isotopes of the same chemical element.
What is an element that has the same atomic number but different mass numbers?
If a sample of an element contains atoms of different mass numbers, the name of the element followed by a hyphen and the mass number is the name of an isotope of the element.
Can an element have many gram atomic weights?
No, not really. An element has a single atomic weight, which is the weighted average of all the isotopes of that element, weighted by their natural abundance. Each element only has a single atomic weight.What this means is that different atoms of a single element can weigh different amounts because different isotopes have different numbers of neutrons. However, the atomic weight represents the average for all forms of that element, and so there is only one value. The different isotopes of an element certainly have different mass numbers, which is just the sum of the number of neutrons and protons however.
Define the term isotope explain how two isotopes of an element are different?
Isotopes are atoms of the same element that have different numbers of neutrons. Different isotopes of an element have the same atomic number, but different mass numbers. I hope I helped! ^_^
Atoms of the same element with different atomic masses?
what is an atom of the same element with different mass numbers
