ACC Biology Accuplacer Study Guide question and Answer
Atomic Structure Correct Answer: Protons and neutrons make up the nucleus of an atom.The nucleus
... [Show More] is surrounded by a cloud of negatively charged electrons which are bound to the nucleus by an electromagnetic force.
Identifying Elements Correct Answer: Elements are arranged based on their atomic and mass numbers on the periodic table of elements. As you go across the table the atomic weight increases.
Radioisotopes Correct Answer: A naturally or artificially produced radioactive isotope of an element.
Molecules Correct Answer: The smallest possible amount of a particular substance that has all the characteristics of that substance. Formed when two or more atoms join together chemically.
Compounds Correct Answer: A molecule that contains at least two different elements.
The role of electrons in chemical bonding Correct Answer: The electron in the outermost shell of an atom chemically bonds with another atom. Electrons have a negative charge and orbit around the nucleus in the electron shells.
Chemical equation Correct Answer: A symbolic representation of the starting substances(reactants) and the chemical formula of the products.
Energy flow in chemical reactions Correct Answer: Two possible situations:
1.The internal energy of the products is less then the internal energy of the reactants.(exergonic reaction)
2.The internal energy of the products is more then the internal energy of the reactants.(endergonic reaction)
Reversible chemical reactions Correct Answer: The reactants and products are never fully consumed.They are each constantly reacting and being produced.
Irreversible chemical reactions Correct Answer: Reactions in which the reactants convert to products and where the products cannot convert back to the reactants.
Inorganic compound Correct Answer: Any compounds lacking carbon atoms, or when present is ionically bond to other atoms.
Water Correct Answer: An inorganic compound that does not contain any carbon atoms.
Acids Correct Answer: Dissociates in water into electrolytes.A substance that releases hydrogen ions (H+) in solution.
Bases Correct Answer: A substance that releases hydroxyl ions (OH-) in solution, or one that accepts H+ already present in solution.Dissociates in water into electrolytes.
Salts Correct Answer: Dissociates completely in water. The positive and negative regions on the water molecule attract the negative chloride and positive sodium ions, pulling them away from each other.
Organic compounds Correct Answer: Any member of a large class of gaseous, liquid, or solid chemical compounds whose molecules contain carbon. [Show Less]