Chemistry atom

• Atom


  The smallest unit of an element that retains its chemical properties
• Atom


  • Can be split into smaller parts
• Atomic Structure


  1. Nucleus

  2. Electrons surrounding the nucleus in the form of "electron cloud"

  
• Atoms consist of protons, electrons and neutrons

  
• Protons and neutrons are found in the nucleus while electrons surround the nucleus

  
• 99.99% of the mass of an atom is concentrated in the nucleus
• Atomic symbol


  A unique 1-2 letter symbol assigned to each element, with the first letter capitalized
• The symbol may not match the name of the element, as it often had a different name to start with
• Proton number (Z)


  The total number of protons in the nucleus of an atom

  
• Nucleon number (A)


  The total number of protons and neutrons in the nucleus of an atom

  
• In a neutral atom, the number of protons is equal to the number of electrons
• In a positive ion, the number of electrons is less than the number of protons, while in a negative ion the number of electrons is more than the number of protons
• Bohr model of the atom


  1. Electrons move around the nucleus in fixed circular paths called orbitals

  2. Orbitals have fixed energy values called quantum levels

  
• In the Bohr model of the hydrogen atom, the lone electron revolves around the nucleus in fixed circular paths (orbits) with different radii, and each orbit is associated with a fixed energy
• The energy of the orbits increases with their distance from the nucleus, and the orbits are normally referred to as electronic shells or principal shells
• An electricity neutral atom bears what trait?

  it contains the same number of electrons and protons
• the mass number of an atom is equal to its ___________number plus its ____________________number
• Isotopes of the same element vary in the number of____they contain.
• The atomic number of an atom represents how many __________ it has.
• A nuclide is represented by the symbol __________
• A chemical bond is formed when atoms share or exchange __________.
• Atoms that have the same atomic numbers but different masses are called __________.
• Ionic compounds form because they have opposite charges. The positive charge comes from __________, while the negative charge comes from __________.
• The chemical properties of an atom depend on its __________number
• Ionic bonds are formed between oppositely charged __________
• The nuclear charge of an atom is determined by its __________number
• Ions can be positive, negative, or neutral depending on whether they have gained or lost electrons.
• The total number of neutrons and protons in an atom is called its __________number
• Covalent bonds form between nonmetal atoms that have shared pairs of valence __________
• An ion is an atom with a net charge due to having gained or lost electrons.
• An anion is a negatively charged ion.
• Non-metals gain electrons to form negatively charged ________.
• A cation is a positively charged ion.
• Isotopes are atoms with the same ____________________ but different ___________________. Isotopes can be found within the same element.
• Covalent bonds are formed between nonmetal atoms with similar electronegativities.
• Metals lose electrons to form positively charged ________.
• An element's mass number is equal to the sum of its protons and neutrons, which means that the mass number equals the ________.
• Covalent bonds are formed between nonmetal atoms.
• Metallic bonds occur within metals, where delocalized electrons move freely throughout the metal lattice. These types of bonds occur because all metals want to lose ____________.
• Cations are positively charged ions.