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33 Cards in this Set
- Front
- Back
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What three subatomic particles make up atoms?
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Protons, Neutrons and Electrons
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How are all of the isotopes of an element similar?
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Because they have the same number of electrons, all isotopes of an element have the same chemical properties. (They have a different number of neutrons.)
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What are the two main types of chemical bonds?
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The main types of chemical bonds are ionic bonds and covalent bonds.
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Helium atoms contain protons, neutrons, and electrons. The positively charged protons and uncharged neutrons are bound together in the dense nucleus, while the negatively charged electrons move in the space around the nucleus.
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Helium
Atomic number = 2 Mass number = 4 |
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Because they have the same number of electrons, these isotopes of carbon have the same chemical properties. The difference among the isotopes is the number of neutrons in their nuclei.
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Nonradioactive carbon-12
6 electrons 6 protons 6 neutrons Nonradioactive carbon-13 6 electrons 6 protons 7 neutrons Nonradioactive carbon-14 6 electrons 6 protons 8 neutrons |
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What information is contained in a chemical formula?
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The number and types of atoms in a molecule
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ionic bond
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The chemical bond in which electrons are transferred from one atom to another. Example: Sodium + Chlorine = Sodium Chloride
Sodium (Na) + Chlorine (Cl) = NaCl 1 valence elec. 7 valence elec. Na(+1)Cl(-1) |
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Covalent bond
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The chemical bond in which electrons are shared between atoms. Example: In a water molecule, (H2O) each hydrogen atom shares two electrons with the oxygen atom. (co = together + valen = power, strength)
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atom |
The smallest possible particle of an element |
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proton |
a subatomic particle with a single unit of positive electrical charge |
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neutron |
a subatomic particle that is electrically neutral |
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electron |
a subatomic particle with a single unit of negative electrical charge |
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An element's physical and chemical characteristics depend on..... |
...the number and arrangement of its subatomic particles |
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Nucleus |
the tightly packed central core of an atom, composed of its protons and neutrons |
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All atoms of a particular element have the same number of protons, which is known as the element's ________ |
atomic number |
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Isotopes of an element have the same number of ________ but a different number of ________. |
protons, neutrons |
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How is the isotope written for a carbon atom with 6 neutrons? |
Carbon - 12 or superscript 12C |
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Radioactive isotope |
One in which the nucleus decays or breaks down over time, giving off radiation in the form of matter and energy. (example, Carbon-14, but not Carbon-12 or Carbon-13.) |
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Electrons differ in what two ways? |
The amount of energy they have and how tightly they are held by the protons in the nucleus. This is described as belonging to certain energy levels. |
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List the first seven energy levels starting closest to the nucleus and how many electrons each can hold. |
2 8 8 18 18 32 32 |
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Valence electrons |
the electrons held in an atom's outermost energy level, that can be transferred or shared with another atom |
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ions |
atoms or groups of atoms that have become electrically charged as a result of gaining or losing electrons |
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Chemical reaction |
Breaking of existing chemical bonds in reactants and formation of new ones in products (one or more new substances), neither creating nor destroying atoms but only rearranging them. |
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polar molecule |
A molecule in which opposite ends have opposite electric charges, such as water. |
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Hydrogen bond |
The weak attraction between the slightly positive hydrogen atom in one molecule with a slightly negative atom in another molecule. Because no electrons are transferred or shared, this is a weaker bond than ionic or covalent. |
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List 5 unique properties of water |
1) cohesion 2) adhesion 3) temperature moderation 4) lower density in solid state than in liquid, and 5) ability to dissolve other substances |
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Cohesion |
Tendency of molecules of the same kind to stick to one another |
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Adhesion |
Attraction between unlike molecules |
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Temperature moderation |
the ability to resist temperature change |
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Explain the low density of ice |
The 4 long lasting hydrogen bonds between each neighboring water moleculeaci keep water molecules in ice spaced in a regular pattern, whereas in liquid water the molecules are moving faster and the bonds are more short lived, thus they can fit more closely together. |
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acid |
a chemical compound that donates a hydrogen ion (H+) to a solution. An acid is represented by a low pH number. |
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base |
a chemical compound that removes hydrogen ions (H+) from a solution. A base is represented by a high pH number. |
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buffer |
A substance that causes a solution to resist change to its pH level by accepting or donating H+ ions. |
