Chemistry Deck

• Atoms can be represented by symbols, which include the element symbol (e.g., Na) and mass number (number of protons + neutrons).
• Isotopes are atoms with different numbers of neutrons but the same number of protons.
• The number of protons is equal to the atomic number.
• The periodic table is an arrangement of elements based on their atomic structure.
• Elements are arranged into groups or families with similar properties.
• Mass number = Number of protons + Number of neutrons
• Volume = L x W x H
• Density = mass / volume
• Mass = Density x Volume
• Physical properties are properties that can be observed without changing the substance or forming a new substance. E.G texture, color, viscosity etc.
• Solubility is the ability of a substance to be dissolved.
• A solution is a uniform mixture of two or more pure substances. A simple solution involves two substances that are mixed together. Because it is a uniform solution, one of the substances will need to dissolve into the other substance.
• The substance that is dissolved in the solvent is called the solute.
• The substance that does the dissolving is called the solvent.
• Density is a ratio that compares mass to volume for a given substance. Particles that are closer together will have a higher density. This is because they have a greater mass per unit of volume.
• If an object has a density higher than water, it will sink, but if it has a lower density, it will float.
• This diagram is called the Bohr-Rutherford Ion

  
• The rule for electrons in an atom is 2:8:8. Meaning the first ring will have 2 electrons, the second ring will have 8 electrons and the third ring will have 8 electrons.
• Noble gases are stable because the outer shell is filled and cannot partake in Chemical reactions.
• This is called lewis diagram, and it shows only the outer shells electrons.

  
• You can find the average number of neutrons in a nucleus by subtracting the atomic mass from the atomic number
• Isotopes exist for certain elements. An Isotope is two or more forms of the same element that contain equal numbers of protons but different numbers of neutrons. Like the Oxygen isotopes.

  
• Carbon has 3 different isotopes. Carbon usually has 6 protons and 6 neutrons. This is known as Carbon 12. However, carbon 13 has 7 neutrons and carbon 14 has 8 neutrons.
• isotopes are electrically neutral because of an equal number of protons and neutrons
• The charge for this ion (Lithium) would be 1+ because its easier to lose one atom rather than gain 7 more.
• the charge for this lithium ion would be 1+ because it would be easier to lose one electron rather than gain 7 more

  
• The charge for this Fluorine ion would be -1 because it would be easier to gain one electron rather than lose 7 electrons

  
• A molecule is a group of atoms that are chemically joined together. For example, the air you breathe contains many different types of molecules like oxygen (O2), and carbon dioxide (CO2).
• An Ionic compound = Non-metal + Metal
• Chemical Formula indicates the type and number in a pure substance
• F2 = 2 fluorine

  KBr = 1 potassium, 1 bromine

  C3H8 = 3 carbon, 8 hydrogen
• Atoms combine to become more stable. The most stable elements in the periodic table are the noble gases. They are the most stable because they have the maximum number of electrons in their outermost shells.
• Elements that don't have the maximum number of electrons in their outermost orbit combine with other elements to obtain this maximum number of electrons. they share an electron.
• there are two types of compounds: Ionic or molecular
• ionic compounds are pure substances usually consisting of at least one metal or non-metal. While combining, each atom changes into an ion. the resulting positive and negative attract each other and forming and ionic bond. Like how Lithium is attracted to Chlorine and forming an ionic bond.

  
• A Molecular compound consists of two or more non-metal atoms
• Sharing of electrons chemical bond between the atoms is called a covalent (or molecular) bond.
• the 7 common diatomic molecules are H2, N2, O2, F2, Cl2, Br2, and I2
• Properties of Molecular compounds.

  Most molecular compounds share the following properties:

  • Can be solids, liquids, and gases at room temperature
  • Usually good insulators but poor conductors of electricity (solid or liquid)
  • Have relatively low boiling points.
• The periodic table is organized by atomic number and electron configuration. The elements are arranged according to their increasing atomic numbers. Elements with similar properties are grouped together on the same column. This arrangement allows us to predict the properties of new elements based on those of known ones.