IndietroGeneral Biology: Chemistry and Chemical Bonds
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Termini in questo insieme (20)
The four states of matter are solid, liquid, gas, and plasma.
An element is a substance that cannot be broken down to a simpler substance by ordinary chemical means and has unique properties.
Carbon, Hydrogen, Nitrogen, Oxygen, Phosphorus, and Sulfur make up about 95% of the body weight of living organisms.
A molecule is any group of 2 or more atoms held together by chemical bonds. A compound contains atoms of different kinds in a fixed ratio. All compounds are molecules, but not all molecules are compounds.
An atom is the smallest part of an element that displays the properties of that element.
Atoms are composed of protons (positive charge), neutrons (no charge), and electrons (negative charge).
The atomic number is the number of protons in the nucleus of an atom and also equals the number of electrons in a neutral atom.
Isotopes are atoms of the same element with different numbers of neutrons.
Potential energy is the energy matter has due to its location or structure; electrons have potential energy based on their energy level or shell.
The distribution of electrons in the electron shells, especially the number of valence electrons, determines an atom's chemical behavior.
An electron orbital is the three-dimensional space where an electron is found 90% of the time within an electron shell.
A covalent bond is the sharing of a pair of valence electrons by two atoms.
A single bond shares 1 pair of electrons, a double bond shares 2 pairs, and a triple bond shares 3 pairs of valence electrons.
Electronegativity is an atom's attraction for electrons in a covalent bond; higher electronegativity means stronger pull on shared electrons.
Non-polar covalent bonds share electrons equally; polar covalent bonds share electrons unequally due to differences in electronegativity, creating partial charges.
An ionic bond forms when atoms transfer electrons, creating oppositely charged ions that attract each other.
Cations are positively charged ions; anions are negatively charged ions.
Hydrogen bonds form when a partially positive hydrogen atom in one polar molecule is attracted to a partially negative atom in another polar molecule.
Van der Waals interactions are weak attractions between molecules caused by temporary uneven electron distributions creating 'hot spots' of charge.
Molecular shape determines how biological molecules recognize and interact with each other; molecules with similar shapes can have similar biological effects.