Elements, Isotopes & Relative Atomic Mass (Chemistry)

• What is an atom made up of?

  An atom is made up of a central nucleus comprising protons and neutrons, with electrons orbiting around it.
• What determines which element an atom is?

  The number of protons in the nucleus determines which element an atom is.
• What is the smallest element and how many protons does it have?

  The smallest element is hydrogen, which has one proton in its nucleus.
• How many protons and neutrons does helium have?

  Helium has two protons and two neutrons in its nucleus.
• How many different elements are there approximately?

  There are around 100 different elements.
• What is the periodic table?

  • Organized chart of elements
  • Each box represents a different element
  • Boxes are called nuclear symbols
• What does the number in the bottom left of a nuclear symbol represent?

  The number in the bottom left is the atomic number, which is unique to that element.
• How can you identify an element using its atomic number?

  Any atom with a specific number of protons must be that element.
• If an atom has two protons, which element is it?

  It must be helium, as helium's atomic number is two.
• What is the atomic number of carbon?

  The atomic number of carbon is six.
• What happens if an atom has three protons?

  It cannot be carbon; it must be the element with atomic number three, which is lithium.
• What does the symbol 'C' stand for?

  'C' stands for carbon.
• What does the symbol 'Li' represent?

  'Li' represents lithium.
• What are isotopes?

  Isotopes are different forms of the same element that have the same number of protons but a different number of neutrons.
• What is the most common form of carbon?

  The most common form of carbon is carbon-12.
• How many protons, neutrons, and electrons does carbon-12 have?

  Carbon-12 has six protons, six neutrons, and six electrons.
• What is the mass number of carbon-13?

  The mass number of carbon-13 is 13.
• Why do isotopes react chemically in the same way?

  Because they all have the same number of protons.
• What is relative atomic mass?

  Relative atomic mass is the average mass of all the isotopes that make up a particular element.
• What does abundance refer to in the context of isotopes?

  Abundance refers to how common or rare that isotope is.
• How do you calculate the relative atomic mass of copper?

  You multiply each isotope's abundance by its mass, sum these figures, and divide by the total abundance.
• What is the equation for relative atomic mass?

  Relative atomic mass = (sum of isotope abundance × isotope mass) / (sum of abundances of all isotopes).
• What is the abundance of copper-63 and copper-65?

  Copper-63 has an abundance of 69.2%, and copper-65 has an abundance of 30.8%.
• What is the first step in calculating the relative atomic mass of copper?

  The first step is to multiply each isotope's abundance by its mass.
• What is the final relative atomic mass of copper rounded to one decimal place?

  The relative atomic mass of copper is 63.6.
• What symbol denotes relative atomic mass?

  The symbol for relative atomic mass is 'Ar'.
• What does the average mass of a copper atom represent?

  The average mass of a copper atom represents the relative atomic mass of copper.