What is an atom and what are its parts?
The basic unit of a chemical element.
What is the valence number of an element?
The number of electrons that can form compounds with other atoms.
What is an isotope?
The same number of protons and electrons, thus they have the same atomic number and the same chemical reactions.
But they have different numbers of neutrons giving them different atomic masses.
What are the types of chemical bonds?
♦Ionic - 1 or more atoms transfered from 1 atom to another
♦Covalent - Sharing of electrons between atoms
What is the difference between an acid and a base?
An acid solution has a higher concentration of H3O+ than OH- and its pH is lower than 7.
A basic solution has a higher concentration of OH- than H3O+ and its pH is higher than 7.
A neutral solution has exactly equal concentration of each one and its pH is exactly 7.
What are the 4 organic compounds? Made of?
♦Carbohydrates - Monosacariates - Carbon, hydrogen, oxygen
♦Nucleic Acids - Nucleotide - Carbon, hydrogen, oxygen, nitrogen, phosphorous atoms
♦Proteins - Amino acids - Carbon, hydrogen, oxygen, nitrogen
♦Lipids - Glycerole molecule, fatty acids - Carbon, hydrogen