Atoms

• What are atoms made of?

  Atoms are made of protons, neutrons, and electrons.
• How small are atoms compared to visible objects?

  Atoms are too small to see, even with a microscope.
• What is the approximate number of atoms in a substance?

  About \(7.74 \times 10^{22}\) atoms.
• What is the radius of an atom?

  The radius of an atom is about \(1 \times 10^{-10}\) m.
• What are the main components of an atom's nucleus?

  • Protons
  • Neutrons
  • Positive charge due to protons
  • Almost all mass of the atom is concentrated here
• What is the radius of the nucleus?

  The nucleus has a radius of around \(1 \times 10^{-15}\) m.
• Why does the nucleus have a positive charge?

  Because it contains protons, which are positively charged.
• Where do electrons move in an atom?

  Electrons move around the nucleus in electron shells.
• What is the charge of electrons?

  Electrons have a negative charge.
• How does the size of electron orbits affect the atom?

  The size of their orbits determines the size of the atom.
• What is the mass of electrons compared to protons and neutrons?

  Electrons have virtually no mass.
• What is the relationship between protons and electrons in an atom?

  • Atoms are electrically neutral.
  • They have the same number of protons and electrons.
  • The charges cancel out.
• What happens in an ion regarding protons and electrons?

  In an ion, the number of protons does not equal the number of electrons.
• What does a 2− charge in an ion indicate?

  An ion with a 2− charge has two more electrons than protons.
• What do atomic number and mass number tell you about an atom?

  • Atomic number indicates the number of protons.
  • Mass number indicates the total number of protons and neutrons.
  • To find neutrons, subtract atomic number from mass number.
• What is the atomic number of an atom?

  The atomic number tells you the atomic (proton) number.
• How do you calculate the number of neutrons in an atom?

  Subtract the atomic number from the mass number.
• What is the nuclear symbol for sodium?

  The nuclear symbol for sodium is \(^{23}_{11}\text{Na}\).
• What is the mass number of sodium?

  The mass number of sodium is 23.
• What is the atomic number of sodium?

  The atomic number of sodium is 11.
• What is the significance of understanding atomic structure in chemistry?

  • It forms the basis for understanding chemical reactions.
  • It helps in grasping more complex chemistry concepts.
  • Essential for GCSE Chemistry success.
• What is the relative mass and charge of a proton?

  Proton has a relative mass of 1 and a charge of +1.
• What is the relative mass and charge of a neutron?

  Neutron has a relative mass of 1 and a charge of 0.
• What is the relative mass and charge of an electron?

  Electron has a very small relative mass and a charge of -1.
• What are isotopes?

  • Atoms of the same element with different numbers of neutrons.
  • They have the same atomic number but different mass numbers.
  • Example: Carbon-12 and Carbon-14.
• How is atomic structure related to the periodic table?

  • Elements are arranged by atomic number.
  • Atomic structure determines chemical properties.
  • Understanding atomic structure aids in predicting element behavior.