The atomic nucleus contains bound neutrons and protons. The same chemical element can have a different number of neutrons and still be the same element. We call isotopes atoms of the same element with different numbers of neutrons.
Part 2: All the atoms of a certain element are identical in mass and properties. Atoms of the same element can have different masses because the number of neutrons for the different isotopes of a given element can vary.
The number of protons an atom has in its nucleus is given by its atomic number. Atomic mass indicates how many protons and neutrons an atom has in its nucleus. Atoms with the same atomic number but different mass numbers are called isotopes. However, they have different numbers of neutrons.
Valence electrons determine the behavior of the atom. The whole behavior of electrons is based on the number of protons.
An element is a substance made up entirely of a certain type of atom. The element hydrogen, for example, is made up of atoms that contain only one proton and one electron. All isotopes of a given element have the same number of protons but can have a different number of neutrons.
Electrically neutral atoms can exist without electrons. So an atom cannot have electrons like it does, it has protons by definition and to be neutral it must have electrons. You can have an ion, like a hydrogen ion (you can call it a proton).
Atoms cannot be created or destroyed and are indestructible, they cannot be broken down into smaller pieces. This was based on the law of conservation of mass. It was later discovered that atoms can break apart into smaller pieces. When atoms of different elements form compounds, they are combined in an integer ratio.
Atoms are made up of electrons, protons and neutrons. Cells can live, but molecules don’t live separately. Life is a systemic quality. Organisms made up of cells live.
Neutron stars are made up of neutrons, so there are definitely no atoms. Even the rare matter found among stars or galaxies, which makes up most of the mass of the universe (!) (Excluding dark matter), is largely not made up of atoms. Apparently it is a plasma-like mixture of protons and electrons.
All matter is made up of atoms. Atoms are indivisible and indestructible. All the atoms of a given element are identical in mass and properties.
Dalton’s atomic theory states that all matter is made up of atoms, indivisible and indestructible bricks. Although all the atoms in an element are the same, different elements had atoms of different sizes and masses.
Scientists have just shown how a single atom can be split into two parts, separated and put back together. Although the word atom literally means indivisible, the laws of quantum mechanics allow atoms to divide and reunite atoms as rays of light.
An atom consists of a positively charged nucleus surrounded by one or more negatively charged particles, the electrons. The number of protons in the nucleus equals the number of electrons surrounding it, which gives the atom a neutral charge (neutrons have no charge).
The total charge on an atom is zero. Atoms are made up of positively charged particles called protons and negatively charged particles called electrons and uncharged particles called neutrons.
The mass number (symbol A, from the German word atomic weight [atomic weight]), also called atomic mass or number of nucleons, is the total number of protons and neutrons (called nucleons together) in an atomic nucleus. The mass number is different for each isotope of a chemical element.
An atom is a fundamental element of matter. An atom itself is made up of three small particles called subatomic particles: protons, neutrons, and electrons. Protons and neutrons make up the center of the atom, the nucleus and electrons fly around the nucleus in a small cloud.
An element is a substance made up entirely of a certain type of atom. For example, the element hydrogen is made up of atoms that contain a single proton and a single electron. When you change the number of protons in an atom, you also change the type of element it has.
Electrons are the smallest of the three particles that make up atoms. Electrons are in shells or orbitals that surround the atomic nucleus. The nucleus contains protons and neutrons. They are grouped in the center of the atom.