Chemistry - atomic structure and periodic table

• What are atoms considered to be?


  Atoms are the basic units of matter.
• What does the nucleus of an atom contain?

  The nucleus contains protons and neutrons.
• What surrounds the nucleus of an atom?

  A cloud of electrons surrounds the nucleus.
• How small are atoms typically?


  Atoms are typically around \(10^{-10}\) meters in diameter.
• How does the size of the nucleus compare to the size of the atom?

  The nucleus is much smaller, about \(10^{-15}\) meters, but contains most of the atom's mass.
• What occupies most of the atom's volume?

  Electrons occupy most of the atom's volume.
• What are the three main subatomic particles that make up an atom?

  The three main subatomic particles are protons, neutrons, and electrons.
• What charge do protons have?

  Protons have a positive charge.
• What charge do neutrons have?


  Neutrons are neutral particles and have no charge.
• What charge do electrons have?

  Electrons have a negative charge.
• How does the mass of an electron compare to that of protons and neutrons?


  The mass of an electron is about \(1/1836\) of a proton and is often considered negligible.
• What determines the identity and properties of an atom?

  The number and arrangement of protons, neutrons, and electrons determine the identity and properties of an atom.
• What is the atomic number (Z)?

  The atomic number is the number of protons in the nucleus.
• What does the mass number (A) represent?


  The mass number represents the total number of protons and neutrons in the nucleus.
• How is the mass number calculated?

  The mass number is calculated as the sum of protons and neutrons in the nucleus.
• If a carbon atom has an atomic number of 6, what is its mass number if it has 6 neutrons?

  The mass number is 12 (6 protons + 6 neutrons).
• How can you calculate the number of neutrons in an atom?

  You can calculate the number of neutrons using the formula: Neutrons = Mass Number - Atomic Number.
• An atom has an atomic number of 8 and a mass number of 18. How many neutrons does it have?

  The atom has 10 neutrons.
• What are isotopes?


  Isotopes are atoms of the same element that have the same atomic number but different mass numbers.
• How are isotopes represented in notation?

  Isotopes are represented as ${^A_Z}X$, where X is the element symbol, A is the mass number, and Z is the atomic number.
• What is the relative atomic mass of an element on the periodic table?

  The relative atomic mass is the weighted average of its isotopes' masses.
• What are the common isotopes of carbon?

  The common isotopes of carbon are Carbon-12, Carbon-13, and Carbon-14.
• What are the properties of isotopes?

  Isotopes have the same chemical properties but slightly different physical properties.
• What does electronic configuration refer to?

  Electronic configuration refers to the arrangement of electrons in an atom's orbitals.
• How do electrons fill the energy levels in an atom?

  Electrons fill shells from the lowest energy level upwards.
• What are the maximum number of electrons that can occupy the first three shells?

  The first shell can hold 2 electrons, the second shell can hold 8 electrons, and the third shell can hold 18 electrons (but often only 8 in the first 20 elements).
• What is the electronic configuration of a neutral sodium atom (atomic number 11)?

  The electronic configuration is 2,8,1.
• What is the structure of the Periodic Table?

  The Periodic Table is a systematic arrangement of chemical elements, organized based on their atomic structure and properties.
• How are elements arranged in the Periodic Table?

  Elements are arranged in order of increasing atomic number.
• What are the columns in the Periodic Table called?


  Columns are called groups or families.
• What are the rows in the Periodic Table called?

  Rows are called periods.
• What do elements in the same group have in common?

  Elements in the same group have similar chemical properties.
• How is the Periodic Table divided?

  The Periodic Table is divided into metals, non-metals, and metalloids.
• What are the blocks in the Periodic Table based on?

  The blocks in the Periodic Table are based on the electron subshell being filled: s, p, d, and f.
• What does the electronic configuration 2, 8, 1 indicate about the electron distribution in a sodium atom?

  The first shell has 2 electrons, the second shell has 8 electrons, and the third shell has 1 electron.
• What are the key features of the Periodic Table?

  - Arranged in order of increasing atomic number - Columns are called groups or families - Rows are called periods - Elements in the same group have similar chemical properties - Divided into metals, non-metals, and metalloids - Categorized into blocks: s, p, d, and f
• How many groups are there in the modern periodic table?

  18 groups
• How many periods are there in the main body of the Periodic Table?

  7 periods
• What happens to the atomic number as you move across a period in the Periodic Table?

  The atomic number increases by one each time.
• What is the relationship between elements in the same group of the Periodic Table?

  Elements in the same group have similar chemical properties.