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49 Cards in this Set
- Front
- Back
- 3rd side (hint)
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What is matter? |
Anything that takes up space and has mass. |
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What states can matter exist as? |
Solid, liquid, and gas. |
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Matter is composed of what? |
Elements. |
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What is an element? |
A substance that cannot be broken down into another substance by ordinary chemical means. |
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How many naturally occurring elements exist? |
92 |
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What four elements make up 96% of the body weight of most living organisms? |
Carbon, hydrogen, oxygen, and nitrogen. |
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What does the atomic theory state? |
That elements consist of atoms. |
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What is the atomic symbol? |
The one or two letter name of the atom or element. |
Na or H |
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What charge are neutrons? |
Neutral |
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Where are neutrons found? |
In the nucleus. |
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What charge are protons? |
Positive |
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Where are protons found? |
In the nucleus. |
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What charge are electrons? |
Negative |
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Where are electrons found? |
Outside the nucleus. |
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What is the mass number equal to? |
The sum of protons and neutrons. |
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The atomic weight does not change with gravity: t or f? |
False. Mass does not change with gravity. |
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What is the atomic number? |
The number of protons in an element. |
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What are isotopes? |
Atoms of the same element that differ in number of neutrons. |
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Isotopes have different mass numbers: t or f? |
True. |
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For atoms up through number twenty, how many electrons are in each shell? |
2 in the first, 8 in each additional. |
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What is the valence shell? |
Outermost shell. |
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What is a molecule chemical bond? |
Group of atoms bonded together. |
H2O |
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What is a compound chemical bond? |
Molecule containing atoms of more than one element. |
Also H2O |
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What are the two types of compound bonds? |
Ionic and Covalent |
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What is an ionic bond? |
The attraction between opposite charges. |
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What is a covalent bond? |
Sharing electrons to complete outer shell. |
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How do we write a structural formula? |
With straight lines. |
H-H; H=H |
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How do we write a molecular formula? |
Show the number of atoms involved. |
H2 |
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Single atoms CANNOT form bonds with more than one atom: t or f? |
False. |
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What are reactants? |
Molecules that participate in reactions |
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What are products? |
Molecules formed by reactions. |
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What is a balanced equation? |
Occurs if the same number of each type of atom occurs on both sides of the arrow. |
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How does the arrangement of electrons relate to the location on the periodic table? |
"Period" identifies how many orbitals or rings of electrons are around the nucleus, while group identifies how many electrons are in the outer orbital. |
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What substance has a polar covalent bond? |
Water. |
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What is a hydrogen bond? |
A slightly positive hydrogen of one water molecule is attracted to the slightly negative oxygen in another water molecule. |
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What are the properties of water? |
Solvency, cohesion and adhesion, high surface tension, high heat capacity, high heat of vaporization, and varying density. |
6 |
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Is water a solvent? |
Yes. Due to polarity and H-bonding, water dissolves many substances. |
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What is hydrophilic |
Molecules that are attracted to water |
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What is hydrophobic |
Molecules that are not attracted to water. |
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What is cohesion? |
Ability of water molecules to cling to each other due to hydrogen bonding. |
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What is adhesion? |
Ability of water molecules to cling to other polar surfaces |
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Wha do acids release? |
Hydrogen ions. |
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What do basics do? |
Take up hydrogen ions or release hydroxide ions. |
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What is the pH scale? |
Mathematical way to indicate the number of hydrogen ions in solution. |
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Acidic or basic: pH below 7 |
Acidic |
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Acidic or basic : pH above 7 |
Basic. |
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What is a pH of 7? |
Neutral. |
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What is a buffer? |
A chemical or combination of chemicals that keeps pH within normal limits. |
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How does a buffer resist pH change? |
By taking up excess H+ or OH-. |
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