Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Chemistry Review • What are subatomic particles? • Protons • Electrons • Neutrons • What are their charges ? • Protons = + • Electrons = • Neutrons = neutral • Where are they found ? • Protons = nucleus • Electrons = shells/ energy levels in the electron cloud (smallest particle) • Neutrons = nucleus • What is the nuclear model of the atom ? • An atom is the smallest unit of an element that upholds all of the properties of that element. • What is the mass of an atom and how is that determined ? • Everything in the nucleus determines its mass = • Protons + • Neutrons (no charge) • How do atoms define or determine elements ? • Protons have a + electrical charge and electrons have a – charge. Atoms that have the same number of + and – do not have an electrical charge. • How do protons determine an elements’ identity ? • An element can be identified by it’s atomic number = # of protons • How do valence electrons determine an element’s chemical reaction ? • Electrons are located and arranged on energy levels. • 1st shell = 2 / 2nd shell = 8 3rd shell = 18 • Valence Electrons are on outermost shell – have the highest energy • They determine if valence electrons are shared, or stolen, or traded to create new molecules. • The reactivity is determined by how easily and readily they react with the valence electrons from other atoms • Metals transfer electrons to nonmetals when they react. • Nonmetals usually gain or share electrons when they react. • Charged atoms are called Ions • How are elements arranged on the Periodic Table ? • Elements are arranged by increasing order of the atomic # • What does the atomic number represent ? • Atomic # = number of protons (and usually electrons) • What determines the atomic mass of an element ? • Number of protons & neutrons • Everything in the nucleus • Atomic Mass increases when moving to the right and down the periodic table, because of the addition of more atomic particles • What do the columns represent ? What do they tell you ? • Columns are called Groups of Families • All elements in that group have the same # of electrons • What do the rows represent ? What do they tell you ? • Rows are called Periods • Each period tells you how many electron shells the element has. • . What physical and chemical properties are determined by investigating the Periodic Table ? • Elements in the same Group or Family have similar physical and chemical properties. • Earth Metals (1) Highly reactive m • Halogens ( 17 )Reactive nonmetal • Nobel Gase (18) Least reactive • -------Metals • -------> Nonmetals • Zigzag/staircase - metalloids • What defines a chemical reaction? • Atoms of substances rearrange themselves into a new substance. • The Reactants combine to form new Products • What is a Chemical Equation ? • Shows the atomic #’s and molecules making up the reactants and products of a chemical reaction. • Subscript = # of atoms ( on right, below line) • Coefficient = # of molecules ( on the left, big number) • What are the reactants and products of a chemical equation ? • Reactants ------ Product ____+____ ----- ________ • Anything left of the arrow • Anything right of the arrow • Arrow means yields or produces • What are the four signs that indicate a chemical reaction has taken place ? • Produces gas/ bubbles • Change in temperature Endothermic-absorbs energy Exothermic-releases energy • Precipitate forms(clear liquid to a solid • Change in state/color change • What are the five kinds of chemical reactions ? • Synthesis ___+____---> _______ • Decomposition ______- __+__ • Single Replacement __+____-- ______+___ • Double Replacement _____+______-______+_______