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Chapter 2, Section 1
Vocab for 2.1 Biology
Term | Definition |
---|---|
Atom | The smallest unit of an element that maintains the chemical properties of that element |
Atomic Number | The number of protons in the nucleus of an atom; the atomic number is the same for all atoms of an element |
Chemical Bond | The attractive force that holds atoms or ions together |
Compound | A substance made up of atoms of two or more different elements joined by chemical bonds |
Covalent Bond | A bond formed when atoms share one or more pairs of electrons |
Electron | A subatomic particle that has a negative charge |
Element | A substance that cannot be separated or broken down into simpler substances by chemical means; all atoms of an element have the same atomic number |
Ion | An atom, radical, or molecule that has gained or lost one or more electrons and has a negative or positive charge |
Ionic Bond | The attractive force between oppositely charged ions, which form when electrons are transferred from one atom to another |
Isotope | An atom that has the same number of protons (or the same atomic number) as other atoms of the same element do but that has a different number of neutrons (and thus a different atomic mass) |
Mass | A measure of the amount of matter in an object; a fundamental property of an object that is not affected by the forces that act on the object, such as the gravitational force. |
Mass Number | The sum of the numbers of protons and neutrons in the nucleus of an atom |
Matter | Anything that has mass and takes up space |
Molecule | A group of atoms that are held together by chemical forces; a molecule is the smallest unit of matter that can exist by itself and retain all of a substance's chemical properties |
Neutron | A subatomic particle that has no charge and that is located in the nucleus of an atom |
Nucleus | In physical science, an atom's central region, which is made up of protons and neutrons |
Orbital | A region in an atom where there is a high probability of finding electrons |
Proton | A subatomic particle that has a positive charge and that is located in the nucleus of an atom; the number of protons of the nucleus is the atomic number, which determines the identity of an element |