AC HPAT Chemistry Questions All Correct Answers

AC HPAT Chemistry Questions All Correct Answers single displacement - ANSWER- A + BC -- AC + B double displacement - ANSWER- AB + CD -- AD + CB precipitate - ANSWER- A solid that forms from a solution during a chemical reaction. energy level - ANSWER- Energy levels (also called electron shells) are fixed distances from the nucleus of an atom where electrons may be found. What is the atomic number of an element - ANSWER- number of protons What is the mass number of an element - ANSWER- The number of protons and neutrons in the nucleus of an atom. Together, the number of protons and the number of neutrons determine an element's mass number: mass number = protons + neutrons. If you want to calculate how many neutrons an atom has, you can simply subtract the number of protons, or atomic number, from the mass number. Isotopes - ANSWER- Atoms of the same element that have different numbers of neutrons Radio isotopes - ANSWER- unstable isotopes Difference between radioisotopes and isotopes - ANSWER- The key difference between isotopes and radioisotopes is that isotopes may or may not undergo radioactive decay whereas radioisotopes essentially undergo radioactive decay. synthesis reaction - ANSWER- a reaction in which two or more substances combine to form a new compound decomposition reaction - ANSWER- a reaction in which a single compound breaks down to form two or more simpler substances Concept of quanta of energy - ANSWER- In 1913, Niels Bohr proposed a theory for the hydrogen atom, based on quantum theory that some physical quantities only take discrete values. Electrons move around a nucleus, but only in prescribed orbits, and If electrons jump to a lower-energy orbit, the difference is sent out as radiation. What is organic chemistry? - ANSWER- the study of carbon compounds Electronegativity - ANSWER- A measure of the ability of an atom in a chemical compound to attract electrons covalent bond - ANSWER- A chemical bond that involves sharing a pair of electrons between atoms in a molecule functional groups - ANSWER- the components of organic molecules that are most commonly involved in chemical reactions Lewis Dot Structure - ANSWER- diagram of a molecule using dots to represent valence electrons Methane formula - ANSWER- CH4 Butane - ANSWER- C4H10 Ethyne - ANSWER- C2H2 polar covalent bond - ANSWER- A covalent bond in which electrons are not shared equally non polar covalent bond - ANSWER- equal sharing of electrons Characteristics of carbon atom in terms of bonding - ANSWER- Carbon atoms are unique because they can bond together to form very long, durable chains that can have branches or rings of various sizes and often contain thousands of carbon atoms. Silicon and a few other elements can form similar chains; but they are generally shorter, and much less durable. Alkene - ANSWER- double bond (unsaturated) Alkane - ANSWER- single bond (saturated hydrocarbon) Alkyne - ANSWER- triple bond (unsaturated) Addition reaction - ANSWER- A reaction in which a reactant is added to an unsaturated molecule to make a saturated molecule Substitution reaction - ANSWER- A reaction in which an atom or group of atoms is replaced with a different atom or group of atoms. Combustion - ANSWER- the process of burning something Oxidation - ANSWER- loss of electrons reduction - ANSWER- gain of electrons Anode - ANSWER- Negative electrode ( oxidation occurs- electron loss)