Bio-Chem

• the matter

  it is any substance that has mass and volume, and occupy space
• The building unit of any matter is the atom
• The two main parts in the atom : nucleus and the energy levels
• proton (positive charge)
• electrons (negative charge)
• the number of protons = atomic number
• the sum of protons + neutrons = mass number
• isotopes are atoms with same atomic numbers but different mass numbers
• ionic bonding occurs when an atom loses or gains electrons, creating positive/negative ions .
• ionic bonding occurs when an atom loses or gains electrons, resulting in positively charged cations and negatively charged anions.
• covalent bonds occur between nonmetal atoms sharing one or more pairs of valence electrons.
• covalent bonds occur between nonmetals where they share pairs of electrons to form molecules.
• covalent bonds occur between nonmetals where they share pairs of electrons to achieve stable electron configurations.
• Hydrophobic substances do not dissolve in water due to their lack of polarity.
• hydrogen bonds form between hydrogen atoms on polar molecules and lone pair electrons on other nearby polar molecules.
• the sub-particles of the atom: protons , neutrons and electrons
• the charge of the atom is neutral because the number of positive protons equal the number of negative electrons
• Ionic bonds happen between metal and nonmetal substance forming compounds
• The metal can lose electrons to become inactive and become an cation or a positive ion
• Hydrogen Bonds occur between H+ and O-
• covalent bonds occur when two nonmetals share their outermost electron pairs
• Non metals gain electrons to become active and become anions or negative ions
• the pure compounds contain one type of element
• the compound Consists of two or more different elements chemically joining together to form new substance
• a mixture is a substance that contains two or more different elements or compounds that are not chemically combined
• all compounds are molecules but not all molecules are compounds
• there are 2 types for the covalent molecules : polar & non-polar
• non-polar molecules have equal distribution in the electrons between atoms
• polar substance have unequal distribution in electrons
• ionic bonding occurs when an atom loses its outermost electron, forming a positive ion (cation) and another atom gains this electron, becoming a negative ion (anion)
• in the water molecule , one oxygen atom binds with two hydrogen atoms by a covalent bond
• the partial negative oxygen atom binds with partial positive hydrogen atom to connect two water molecules
• water is a polar molecule because it has a partial positive charge on one side and a partial negative charge on the other
• The bond between water molecule is called hydrogen bond .
• the bond between water atoms is covalent bond
• Water can dissolve many substance but it cannot dissolve fatty and non polar substance
• Cohesion is the attraction between molecules of the same substance.
• Adhesion is the attraction between two surfaces that are not in contact with each other.
• surface tension is the force that keeps water droplets from touching the surface of a liquid ; it explains why some insects can walk on water as spiders can
• capillary action happens according to adhesion & cohesion which make the liquid rise against gravitational force