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Ch.2 Terms and Notes
Need to know for the Ch. 1-3 Exam (taken from S.A. study guides and lectures)
Question | Answer |
---|---|
Define: Law of Conservation of Mass | Definition: This states that energy cannot be created or destroyed, but may be changed from one form to another. |
Define: Law of Constant Composition | Definition: This states that samples of a pure compound always contain the same elements in the same mass proportion. |
Define: Proton | Definition: Electrically positive particle in the nucleus. Adding or subtracting these is catastrophic and CAN NOT be done by conventional means. |
Define: Neutron | Definition: Electrically neutral particle in the nucleus. Adding or subtracting these will not affect the elemental name or charge but WILL affect mass and isotopic identity. |
Define: Electron | Definition: Electrically negative particle found in the space surrounding the nucleus. |
Define: Nucleus | Definition: This is the core of an atom, made of protons and neutrons. |
Define: Atomic Mass Unit (u) | The unit of a scall of relative atomic masses of the elements; 1u=1/12 of the mass of a carbon atom with 6 protons and 6 neutrons . . . *** (in other words, it is approximately the mass of 1 proton OR 1 neutron) |
Define: Atomic Number | This is the number of protons in the nucleus of an atom of an element. |
Define: Mass Number (A) | The sum of the number of protons and neutrons in the nucleus of an atom. |
Define: Isotope | Definition: These are Atoms with the same number of protons, but differing numbers of neutrons. They are different forms of a single element. |
Define: Atomic Nuclear Symbol (Isotopic Symbol) | Definition: This consists of three parts: the symbol of the element, the mass number of the specific isotope(top number), and the atomic number of the element (bottom number). |
Define: Atomic Weight . . . Also known as Atomic Mass | Definition: The average mass of atoms of an element, calculated using the relative abundance of isotopes in a naturally-occurring element. It is the weighted average of the masses of naturally-occurring isotopes. |
Define: Atomic Mass . . . Also known as Atomic Weight | Definition: This is the average mass of atoms of an element, calculated using the relative abundance of isotopes in a naturally-occurring element. |
Define: Period (In relation to the Periodic Table) | Definition: In chemistry, this term refers to a horizontal row of the periodic table. |
Define: Group (In relation to the Periodic Table) | Definition: A vertical column in the Periodic Table. |
Identify: Transition Metals ...(using the periodic table, how do you know what these elements are?) | 1)They are the B-Groups. And, 2)Located in the middle section of the periodic table. |
Identify: Inner Transitional Metals ...(using the periodic table, how do you know what these elements are?) | These are found on the insert below the body of the periodic table. ****(because if they were put in their actual location in the middle of the B Groups, the Periodic table would be very long and difficult to put in text books & on posters.) |
Identify: Metals ...(using the periodic table, how do you know what these elements are?) | These are found to the left of the metaloid elements. |
Identify: Nonmetals ...(using the periodic table, how do you know what these elements are?) | These are found to the right of the metaloid elements. |
Identify: Metalloids ...(using the periodic table, how do you know what these elements are?) | B, Si, Ge, As, Sb, Te ---- Not easily identified by a set group or period, but rather the characteristic "stair step" |
Identify: Halogens ...(using the periodic table, how do you know what these elements are?) | This is a common name for the 7A group on the periodic table. |
Identify: Alkali Metals ...(using the periodic table, how do you know what these elements are?) . . . * * * (Note: this is NOT Alkaline with an 'ne' at the end) | This is a common name for the 1A group on the periodic table. |
Identify: Alkaline Earth Metals ...(using the periodic table, how do you know what these elements are?) . . . * * * (Note: this IS Alkaline with an 'ne' at the end) | This is a common name for the 2A group on the periodic table. |
Identify: Noble gases ...(using the periodic table, how do you know what these elements are?) | This is a common name for the 8A group on the periodic table. . . A name given to them because their full electron valence shells make them very stable. |
Identify: 7 Diatomic Elements (Elements that naturally occur in pairs) | He, N, O, F, Cl, Br, I |
Define: Anion | Definition: An ionic species having a negative charge. |
Define: Cation | Definition: An ionic species having a positive charge. |
Define: Polyatomic Ion | Definition: This is an ion comprised of two or more atoms. |
Define: Covalent Bond | Definition: This is a chemical link between two atoms in which electrons are shared between them. |
Define: Ionic Bond | Definition: This is a chemical link between two atoms caused by the electrostatic force between oppositely-charged ions in an ionic compound. |
Define: Molecular Compound . . . Also known as a Covalent Compound | Definition: a molecule formed by covalent bonds, in which the atoms share one or more pairs of valence electrons |
Define: Ionic Compound | Definition: This is a compound formed by ions bonding together through electrostatic forces. |
Define: Binary Compound | Definition: This is a compound made up of two elements. |
Define: Binary IONIC Compound | Definition: This is an ionic compound made up of two elements. |
Define: Binary MOLECULAR Compound | Definition: This is a covalent compound made up of two elements. |
What is Avogadro's Number? | Definition: This is the number of particles found in one mole of a substance. It is the number of atoms in exactly 12 grams of carbon-12. This experimentally determined value is approximately 6.022 x 1023 particles per mole. |
Define: mole | Definition: This is a chemical mass unit, defined to be 6.022 x 1023 molecules, atoms, or some other unit. The mass of a mole is the gram formula mass of a substance. |
Define: Molar Mass | Definition: This is the mass of one mole of a substance, usually expressed in grams or kilograms. |
Define: Empirical Formula | Definition: This is a formula that shows the ratio of elements present in the compound. The ratios are denoted by subscripts next to the element symbols. |
Define: Molecular Formula | Definition: This is an expression which states the number and type of atoms present in a molecule of a substance. |
Define: Percentage Mass Composition | Definition: This is the percentage by mass of each element in a compound. |
Define: Hydrated Compound | Definition: These are compounds in which molecules of water are associated with ions |
What is Dalton's Atomic Theory? | Definition: the theory that matter consists of indivisible particles called atoms and that atoms of a given element are all identical and can neither be created nor destroyed. Compounds are formed by combination of atoms (molecules). |
Where are Alkali Metals found on the periodic table? | Group 1A . . . (Also known as:__?) |
Where are the Alkaline Earth Metals found on the periodic table? | Group 2A . . . (also known as:__?) |
Where are Halogens found on the periodic table? | Group 7A . . . (also known as:__?) |
Where are the Nobel Gases found on the periodic table? | Group 8A . . . (also known as:__?) |
Name 7 elements that are Diatomic under normal conditions (25degC, 1atm) | He, N, O, F, Cl, Br, I |
Name 2 elements that are liquid under normal conditions (25degC, 1atm) | Br, Hg |
Name the group & the elements that are in a gas state under normal conditions (25degC, 1atm) | The Entire 8A Group, plus: N, O, F, Cl |
What Phase (State) is the majority of the Periodic Table found under normal conditions? (25degC, 1atm) | Solid |
What is the difference between Covalent Bond and Ionic Bond? | Covalent Bonds are elements sharing electrons of the Valence Shell (Co-valant). Ionic Bonds are elements (or groups of elements) of opposite electrical charge combined to share a zero charge. |
What is the numerical value of Avogadro's Number? | 6.023 x 10^23 = 1 mole |
Define: Molar Mass? | Definition: The mass (g/mol) of one mole of atoms (6.023x10^23) of an element or substance. |
Define: Molarity | Definition: The moles of solute per kg of solvent |
How is Isotopic Identity changed? | Adding or subtracting electrically neutral Neutrons does this. |
What subatomic particle is directly linked to an elemental identity? (this particle can not be added or subtracted with conventional means) | Protons are the subatomic particle directly linked to this. |
Define Covalent Compound . . . Also known as Molecular Compound | Definition: a molecule formed by covalent bonds, in which the atoms share one or more pairs of valence electrons |