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What is matter?
Definition: anything physically real, occupies space, & has mass.
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Give an example of a mixture. What is a mixture?
Sugar Water.
- a blend of 2 or more substances with
- individual chemical identities
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What is a pure substance and give an example of one?
Uniform in composition & properties i.e. chemical elements & chemical compounds.
- H2O
- Molecular O2, N2, etc...
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Give and example of a physical property and a chemical property. What is the difference between them?
- Physical:color, size, boiling point
- Chemical:combustion, chemical reactivity
Physical properties describe the substance with out altering its chemical makeup, where as a chemical property of a substance describes how that substance interacts with other substances when a chemical change takes place.
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Where would find the metals on the periodic chart? What are the characteristics of metals?
Found on the left side of the periodic table.
- Characteristics:
- -Solid at room temperature
- -Lustrous appearance
- -Malleable
- -Good conductors of heat & electricity
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Where are the nonmetal found on the periodic chart? What are the characteristics of non metals?
On the right side of the periodic table.
- Characteristics:
- -May be solid, liquid, or gas at room temperature.
- -Poor conductors of heat & electricity
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What are the metalloids? Why are they classified as metalloids?
Form a zigzag band between metals & nonmetals on the periodic table.
- properties are intermediate
- between metals and nonmetals.
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What are the four assumptions of the atomic theory?
-All matter is composed of atoms
- -Atoms of one element are alike but differ
- from atoms of all other elements
-Chemical compounds are composed of specific combinations of atoms
-Chemical reactions change only the way atoms are combined, not the atoms themselves
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What is the mass of a neutron?
1.008665 AMU's
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What is the mass of a proton?
1.007276 AMU's
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How many electron can fit in the following subshells respectivley? s,p,d,f
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What is the theory of octet?
Atoms tend to try and fill their valence shell with 8 electrons.
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Characterize the difference between an ionic, covalent and hydrogen bond.
- Covalent is bonding through the sharing of an electron.
- Ionic is bonding by attraction of oppositely charged particles.
- Hydrogen bonding is an interaction between molecules that occurs because of polar differences between electron configurations of the molecules.
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What are electrolytes?
Substances that produce ions and conduct electricity when dissolved in water.
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What is ionization?
Changing of ionically bonded atoms to ions when dissolved in water.
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What is ionization energy?
The energy required to remove an electron from an atom, forming a cation.
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What is electron affinity?
The energy required to add an electron to an atom, forming an anion.
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What is an ion?
an electrically charged atom or group of atoms.
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What is a cation and what are some examples of common cations?
Positively charged ion (Na+) formed when electrically neutral atom loses an electron leaving a net positive charge (more protons than electrons).
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What is an anion? What are some common anions?
Negatively charged ion (Cl-)formed when an electrically neutral atom gains an electron leaving a net negative charge (more electrons than protons).
- Common anions:
- Cl- Chloride
- Po43- Phosphate
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What is molar mass?
A conversion factor between mass in grams and moles.
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What is molarity?
- The number of moles of solute dissolved in 1
- liter of solution.
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What does the Law of conservation of mass state?
Mass is neither created nor destroyed.
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In a chemical reaction, what is a reactant?
- Substance that undergoes a change in a
- chemical reaction.
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In a chemical reaction, what is a product?
- A substance that is formed in a chemical
- reaction.
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What is the bond dissociation energy?
The amount of energy that must be supplied to break a bond and separate atoms from each other. Measures the strength of a covalent bond.
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What is an endothermic reaction or process?
A reaction or process that absorbs heat.
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What is an exothermic reaction or process?
A reaction or process that releases heat.
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What is free energy?
- Released in a spontaneous (exergonic) process
- Absorbed in nonspontaneous (endergonic) process
- Potential energy
- Kinetic energy
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In a reaction, what is the activation energy?
The amount of energy needed to overcome the barrier for a reaction to occur.
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What does activation energy effect?
Determines the rate of a reaction.
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What does adding heat to reaction do?
- ↑ temperature → ↑ energy in the system & more collisions.
- ↑ 10° C causes the rate of the reaction to double.
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How can we decrease the activation energy for a particular reaction?
- Increase the concentration of reactants.
- Add a catalyst.
- Increase the temperature.
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What is a catalyst?
A substance that speeds the rate of the reaction but is itself not changed.
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