FreeNotes
The formation of sodium chloride (NaCl) can be explained using electron dot structures: Step 1: Sodium (Na), an alkali metal, has one electron in its outermost shell (1s² 2s² 2p⁶ 3s¹). Chlorine (Cl), a halogen, has seven electrons in its outermost shell (1s² 2s² 2p⁶ 3s² 3p⁵). Step 2: Sodium donates its single valence electron … Read more
Electronegativity is the ability of an atom to attract shared electrons in a chemical bond. The difference in electronegativity between two atoms determines the type of bond formed: If the difference in electronegativity is small or zero (typically less than 0.5), a non-polar covalent bond is formed, as the electrons are shared equally. If the … Read more
Bond energy (or bond dissociation energy) is the amount of energy required to break one mole of bonds in a molecule in the gas phase. It measures the strength of a chemical bond. The higher the bond energy, the stronger the bond, as more energy is required to break it. Bond energy is typically higher … Read more
Non-polar covalent bond: A non-polar covalent bond forms when two atoms share electrons equally. This typically occurs between two identical non-metals (e.g., H₂, O₂) where the electronegativity difference between the atoms is negligible or zero. As a result, the electron distribution is uniform, and there is no partial charge on the atoms. Polar covalent bond: … Read more
Noble gases (helium, neon, argon, krypton, xenon, and radon) do not form bonds easily because they have a full outer electron shell (a stable electron configuration). This full valence shell makes noble gases chemically inert and stable. Since atoms tend to bond to achieve a stable electron configuration, noble gases already possess the most stable … Read more
An ionic bond is a type of chemical bond that forms between two atoms when one atom donates an electron to another atom, resulting in the formation of positively and negatively charged ions. This bond forms due to the electrostatic attraction between these oppositely charged ions. Typically, ionic bonds form between a metal and a … Read more
(a) State the number of protons and neutrons in the nucleus of this atom. The atomic number tells us the number of protons in the atom. For an atom with an atomic number of 9, there are 9 protons. The mass number is the sum of the protons and neutrons. Therefore, the number of neutrons … Read more
(a) Define the term isotope. An isotope refers to atoms of the same element that have the same number of protons but different numbers of neutrons. This leads to different mass numbers for the isotopes of an element. While isotopes of an element have nearly identical chemical properties, their physical properties, like mass, may differ. … Read more
When metals form cations, they lose electrons. This is because metals tend to have fewer electrons in their outer shell and can achieve a more stable configuration by losing those electrons. Here’s how the cations for the given metals are formed: (a) Barium (Ba): Barium is in Group 2, so it has 2 valence electrons. … Read more
The number of valence electrons corresponds to the number of electrons in the outermost shell of an atom. To find this, we look at the group number in the periodic table: (a) Boron (B): Boron is in Group 13 of the periodic table. Elements in Group 13 have 3 valence electrons. Therefore, boron has 3 … Read more