chemistry paper 1

• What is the topic of the study material provided?

  Atomic Structure and the Periodic Table
• What are the three main subatomic particles found in atoms?

  Protons, Neutrons, and Electrons
• Where is the nucleus located in an atom?

  In the center of the atom
• What charge do protons have?

  Positive charge
• How do electrons move in relation to the nucleus?

  Electrons move around the nucleus in electron shells
• What is the relative mass of an electron?

  Virtually 0
• What does the number of protons in an atom determine?

  The type of element
• What happens to the number of protons and electrons in an ion?

  The number of protons does not equal the number of electrons
• How do you calculate the number of neutrons in an atom?

  Subtract the atomic number from the mass number
• What does the atomic number represent?

  The number of protons in an atom
• What is the mass number of an atom?

  The total number of protons and neutrons in the atom
• What is the nuclear symbol for sodium?

  $^{23}_{11}Na$
• Why is it important to understand basic atomic structure in chemistry?

  It provides a foundation for understanding more complex chemistry concepts
• If an atom has an atomic number of 31 and a mass number of 70, how many neutrons does it have?

  39 neutrons
• What defines an element?

  A substance made up of atoms that all have the same number of protons
• What is the significance of atomic number in elements?

  It determines the identity of the element
• How many different elements are there approximately?

  About 100
• What are isotopes?

  Different forms of the same element with the same number of protons but different numbers of neutrons
• Give an example of isotopes of carbon.

  Carbon-12 and Carbon-13
• What is relative atomic mass?

  The weighted average of the masses of an element's isotopes based on their natural abundance
• How do you calculate the relative atomic mass of an element?

  $\text{Relative atomic mass} =$$\frac{\sum (\text{isotope abundance} \times \text{isotope mass number})}{\sum \text{abundances of all isotopes}}$
• Calculate the relative atomic mass of copper with isotopes Cu-63 (69.2% abundance) and Cu-65 (30.8% abundance).

  63.6
• What is a compound?

  A substance formed from two or more elements that are chemically bonded together
• How are compounds formed?

  By the chemical bonding of atoms from different elements
• What is ionic bonding?

  A type of bonding that occurs when atoms transfer electrons
• Give an example of a compound formed by ionic bonding.

  Sodium chloride (NaCl)
• What is covalent bonding?

  A type of bonding that occurs when atoms share electrons
• What is the formula for water?

  H2O
• How do the properties of a compound compare to the properties of its constituent elements?

  The properties of a compound are usually different from those of the individual elements
• What does a chemical formula represent?

  It shows the types and numbers of atoms in a compound
• What is the formula for sulfuric acid?

  H2SO4
• Why is it important to balance chemical equations?

  To ensure the law of conservation of mass is followed
• What is the balanced equation for the reaction of magnesium with oxygen?

  2Mg + O2 → 2MgO
• What is a mixture?

  A combination of two or more substances that are not chemically bonded
• How can mixtures be separated?

  By physical methods such as filtration and chromatography
• What is chromatography used for?

  To separate different substances in a mixture
• What is the first step in paper chromatography?

  Draw a line near the bottom of a sheet of filter paper
• Why shouldn't you use a pen to draw the line on filter paper for chromatography?

  Because pen ink may dissolve in the solvent
• What happens to the dyes in ink during chromatography?

  They move up the paper at different rates and separate out
• What is the end result of a chromatography experiment called?

  A chromatogram