Biology Quiz Ionic, Covalent, Hydrogen Bonding and the water molecule

Adhesion

water is attracted to other substances. This happens because many other substances have a polar nature as well.

Polar Molecule

this is a molecule that has a positive and negative side that is caused by the atoms within the molecule sharing electrons unevenly. For example, the water molecule is polar because the oxygen side of the molecule has more electrons than the hydrogen side. This causes the oxygen side to have a negative charge and the hydrogen side to have a positive charge. Polar molecules tend to stick to one another (see: adhesion, cohesion) as if they were magnets. The polar nature of the water molecule allows it to dissolve many different ionic and covalent compounds because the water molecule attracts ions and other types of polar molecules.

Acids

Donate/give away hydrogen ions

Diffusion

When particles move from an area of high concentration to an area of lower concentration.

pH

A reference for how acidic or basic a solution is.

Covalent Bond

Bond that occurs between 2 nonmetals as the atoms share valence electrons in order to achieve 8 valence electrons (hydrogen atoms achieve 2 valence electrons). This type of bond forms 'molecules'. Covalent bonds always form between nonmetals and nonmetals.

Ionic Bond

Bond that occurs between 2 oppositely charged ions. This bond occurs after atoms give and take valence electrons in order to achieve 8 valence electrons. Ionic bonds form compounds that are called 'ionic compounds' (not molecules). Ionic bonds always form between metals and nonmetals.

Bases

Donate/give away hydroxide ions

Molecule

Molecules are compounds that results from a covalent bond. Most important biological molecules are molecules.

Hydrogen Bond

This bond is a weak bond that forms when a hydrogen atom within one molecule is attracted to nitrogen, oxygen, or fluorine atoms in another molecule. This bond is important because it keeps many important biological molecules (proteins, carbohydrates, fats) from falling apart/dissolving. Water forms hydrogen bonds between the individual water molecules.

Ionic compound

This is a compound that results from an ionic bond

Capillary Action

occurs when water molecules to creep up thin tubes (example: water creep up the vessels within plants bringing water to the leaves). Capillary action is caused by the polar nature of the water molecule. Capillary action is caused by both adhesion and cohesion.