0
The atomic weight is the average weight of an element when all of the isotopes are averaged. This does not mean that there is a portion of a neutron in the atom.. All of the isotopes of an element have a whole number of protons and neutrons. the atomic weight is the average of all the isotopes found, it is affected by the ratios of the different isotopes. If the number was a whole number then no known isotopes have been found.
Wiki User
∙ 9y ago
Wiki User
∙ 16y agoChlorines Atomic Mass isn't a whole number because it is an average. The Atomic mass is accounting for all of Chlorines Isotopes(an atom having the same number of protons but not the same number of neutrons) example- regular chlorine atom- 17 protons and 18 neutrons one isotope of Chlorine- 17 protons and 19 neutrons
Wiki User
∙ 12y agoChlorine has two stable isotopes: 35Cl & 37Cl that are naturally occurring. Chlorine-35 (17 protons & 18 neutrons) composes about 75.8% of the stable isotopes and chlorine-37 (17 protons & 20 neutrons) is about 24.2%. That's why it is not a whole number, the atomic mass of chlorine is a weighted average of the two stable isotopes. Hope that helps.
Wiki User
∙ 15y agoRelative mass of any atom comes from the average of the mass of the isotopes. Chlorine has 17 protons and can have a variable number of neutrons. The most common isotope has 18 which gives an atomic weight of 35. However chlorine is also stable with 20 neutrons giving it a atomic weight of 37. You may wonder then why isn't the mass of Chlorine 36. The reason for this is that chlorine 35 is more common then chlorine 37. It comprises about 75% of natural chlorine as opposed to 25% for chlorine 35, giving an average atomic weight closer to 35.5.
Hope that helps
Wiki User
∙ 11y agoAtomic mass is the mass of one mole of naturally occurring atoms of an element. In nature chlorine, and other elements occur as a mixture of isotopes. The 2 main isotopes of chlorine are mass numbers 35 and 37, but they do not occur equally. There are about 75 atoms (75%) of the lighter Cl-35 isotope and 25 atoms (25%) of the heavier Cl-37 isotope in each 100 atom sample. Average mass is not found by adding and dividing by 2. Because they do not occur equally the percentage must be taken into account.
75% x 35 + 25% x 37 = 35.5
Notice my answer is not exactly the 35.45 you stated for 2 reasons. 1st -- I said about 75% and 25%. More exact amounts can be found in some books. 2nd -- The real mass of Cl-35 is not 35 due to something called binding energy. Similarly Cl-37 does not have an exact mass of 37,
Wiki User
∙ 12y agoThe relative atomic mass of naturally occurring elements is based upon the abundance of the various isotopes (which have differing masses). Therefore it need not be a whole number.
Wiki User
∙ 11y agoBecause the atomic weight is calculated taking into account th atomic masses of the isotopes of this element and their percentages. The atomic mass of an isotope is never an integer.
Add your answer:
Earn +20 pts
What are the atomic number of an element in a particle?
The number of protons in the nucleus of an atom determines an element's atomic number. In other words, each element has a unique number that identifies how many protons are in one atom of that element. For example, all hydrogen atoms, and only hydrogen atoms, contain one proton and have an atomic number of 1. All carbon atoms, and only carbon atoms, contain six protons and have an atomic number of 6. Oxygen atoms contain 8 protons and have an atomic number of 8. The atomic number of an element never changes, meaning that the number of protons in the nucleus of every atom in an element is always the same.
Definition of atomic mass and atomic number?
the atomic number: The number of protons in the nucleus of an atom determines an element's atomic number. In other words, each element has a unique number that identifies how many protons are in one atom of that element. For example, all hydrogen atoms, and only hydrogen atoms, contain one proton and have an atomic number of 1. All carbon atoms, and only carbon atoms, contain six protons and have an atomic number of 6. Oxygen atoms contain 8 protons and have an atomic number of 8. The atomic number of an element never changes, meaning that the number of protons in the nucleus of every atom in an element is always the same. the atomic mass: it's the sum of neutrons and protons electrons in a single atom. to sum it up the atomic number is the number of protons and the mass number is the total number of every thing in an atom!
What is the atomic mass or mass number?
The number of protons in the nucleus of an atom determines an element's atomic number. In other words, each element has a unique number that identifies how many protons are in one atom of that element. For example, all hydrogen atoms, and only hydrogen atoms, contain one proton and have an atomic number of 1. All carbon atoms, and only carbon atoms, contain six protons and have an atomic number of 6. Oxygen atoms contain 8 protons and have an atomic number of 8. The atomic number of an element never changes, meaning that the number of protons in the nucleus of every atom in an element is always the same.
What number never changes in a neutral atom?
the atomic number never changes
What does it mean to say the atomic number in an atom?
An atom's atomic number is the number of protons an atom has. This number will never change or the atom becomes a totally different atom.
Why is the relative atomic mass of chloride not a whole number?
Because relitive atomic masses are NEVER whole numbers.
Can atoms of different elements have the same number of protons be from the same element?
No. Each type of atom (element) has its own unique number of protons, which is called the atomic number. Atoms of the same element will always have the same atomic number (number of protons). Atoms of different elements will never have the same atomic number (number of protons).
What contributes to an atoms atomic number and to its mass number?
The atomic number is the number of protons in the atom (this can never change). The mass number is the number of protons plus the number of neutrons, this varies because atoms lose neutrons so they take one mole (6.0223x10^23) of the atoms, and average it.
What are the atomic number of an element in a particle?
The number of protons in the nucleus of an atom determines an element's atomic number. In other words, each element has a unique number that identifies how many protons are in one atom of that element. For example, all hydrogen atoms, and only hydrogen atoms, contain one proton and have an atomic number of 1. All carbon atoms, and only carbon atoms, contain six protons and have an atomic number of 6. Oxygen atoms contain 8 protons and have an atomic number of 8. The atomic number of an element never changes, meaning that the number of protons in the nucleus of every atom in an element is always the same.
Definition of atomic mass and atomic number?
the atomic number: The number of protons in the nucleus of an atom determines an element's atomic number. In other words, each element has a unique number that identifies how many protons are in one atom of that element. For example, all hydrogen atoms, and only hydrogen atoms, contain one proton and have an atomic number of 1. All carbon atoms, and only carbon atoms, contain six protons and have an atomic number of 6. Oxygen atoms contain 8 protons and have an atomic number of 8. The atomic number of an element never changes, meaning that the number of protons in the nucleus of every atom in an element is always the same. the atomic mass: it's the sum of neutrons and protons electrons in a single atom. to sum it up the atomic number is the number of protons and the mass number is the total number of every thing in an atom!
True or false atoms of different elements have the same never of protons?
All atoms of the same element are the same.7) Isotopes are a family of atoms all of which have the same number of electrons, have the same number of protons in their atomic centers, but different numbers of neutrons.
What is a a atomic number?
The atomic number of an atom is the atoms number of protons. The number of protons is same as the number of electrons. on a Periodic Table it is usually on top of the elemental abbreviation
What is the atomic mass or mass number?
The number of protons in the nucleus of an atom determines an element's atomic number. In other words, each element has a unique number that identifies how many protons are in one atom of that element. For example, all hydrogen atoms, and only hydrogen atoms, contain one proton and have an atomic number of 1. All carbon atoms, and only carbon atoms, contain six protons and have an atomic number of 6. Oxygen atoms contain 8 protons and have an atomic number of 8. The atomic number of an element never changes, meaning that the number of protons in the nucleus of every atom in an element is always the same.
What number never changes in a neutral atom?
the atomic number never changes
What is the atomic number of an element whose atoms have 9 protons and 10 neutrons?
The atomic number is the number of protons. It is also the number of electrons. The atomic mass equals the protons and neutrons together/weight of the nucleus. So, the atomic number would be nine, because there are 9 protons. The atomic mass would be around 19, because there would be 9 protons and 10 neutrons in the nucleus. The element you are talking about is actually Fluorine, and on the periodic table it says that the atomic mass is 18.9984032. This is because the atomic mass is usually never an exact amount. You can round this decimal place to 19, anyway.
How many atoms in one gram?
To find the number of atoms in a gram you must have the identity of the substance (the molar mass) and solve for the number of moles in 1 gram moles= 1gram / molar mass of substance # atoms = (moles)(Avogadro's number)
How does the atomic number compare with the atomic weight?
The different isotopes have different Atomic Mass numbers, because the isotope has different numbers of neutrons. The protons and electrons are the same, so the change in mass number is the same as the change in the number of neutrons.
