HELP MEEEEEE

• What is a compound?

  A compound is a substance that contains two or more different types of atoms chemically bonded together
• What is the chemical formula for water?

  H₂O
• How many hydrogen atoms are in one molecule of water?

  There are two hydrogen atoms in one molecule of water
• What happens to atoms during a chemical reaction?

  Atoms change what they're bonded to and how they're bonded through chemical reactions
• What is the purpose of balancing chemical equations?

  To ensure the same number of each type of atom on both sides of the equation
• What is the first step in balancing a chemical equation?

  Start balancing atoms that are only in compounds
• How do you balance hydrogen and oxygen in the equation for water?

  By adjusting the coefficients in front of H₂O and O₂
• What is a mixture?

  A mixture is any combination of different types of elements and compounds that aren't chemically bonded together
• How can you separate large insoluble particles from a liquid?

  Using filtration
• What is crystallization used for?

  To separate a solute from a solvent after evaporating the solvent
• What is the process of distillation?

  Heating a solution to separate components based on boiling points
• What is fractional distillation?

  A method to separate different liquids in a mixture based on their boiling points
• What are the three main states of matter?

  Solid, liquid, and gas
• How do particles behave in a solid state?

  Particles vibrate around fixed positions
• What happens to water when it evaporates?

  It changes from a liquid to a gas as particles gain energy
• What is the role of energy in melting or evaporating a substance?

  Energy is supplied to overcome the electrostatic forces of attraction between particles
• What do state symbols indicate in chemical equations?

  They indicate the state of substances: (s) for solid, (l) for liquid, (g) for gas, and (aq) for aqueous
• Who proposed the plum pudding model of the atom?

  JJ Thompson
• What did Ernest Rutherford discover about the atom?

  The positive charge is concentrated in a small nucleus
• What are electrons said to exist in?

  Electrons exist in shells or orbitals around the nucleus
• What are protons and neutrons collectively known as?

  Nucleons
• What is the charge of a proton and an electron?

  Protons have a charge of +1 and electrons have a charge of -1
• What does the atomic number represent?

  The atomic number represents the number of protons in the nucleus
• What happens when an atom gains or loses electrons?

  It becomes an ion
• What is the mass number of an atom?

  The mass number is the total number of protons and neutrons in the nucleus
• What are isotopes?

  Isotopes are atoms of the same element with different numbers of neutrons
• How is the average relative atomic mass calculated?

  By considering the relative abundance of isotopes
• What did Dmitri Mendeleev contribute to the periodic table?

  He grouped elements based on their properties and left gaps for undiscovered elements
• How do electrons fill the shells around the nucleus?

  Electrons fill shells from the inside out, with a maximum of 2 in the first shell and 8 in the second and third shells
• What are the properties of metals in the periodic table?

  Metals donate electrons to achieve a full outer shell
• What are the properties of nonmetals in the periodic table?

  Nonmetals accept electrons to achieve a full outer shell
• What does the acronym PANIC stand for in electrolysis?

  Positive Anode Negative Is Cathode
• What are the alkali metals?

  Group 1 elements that have one electron in their outer shell
• What is the role of the electrolyte in electrolysis?

  It is the substance being electrolyzed to split it up
• What are the two types of electrolytes mentioned?

  Molten and aqueous solutions
• How does reactivity change in alkali metals as you go down the group?

  Reactivity increases as you go down the group
• What happens to ions in a molten electrolyte?

  It contains only the ions of the compound
• What additional ions are present in an aqueous solution compared to a molten electrolyte?

  Hydrogen and hydroxide ions from water
• How does reactivity change in halogens as you go down the group?

  Reactivity decreases as you go down the group
• What are the products of electrolysis for molten sodium chloride?

  Sodium and chlorine