Common Elements and Compounds in Everyday Life

Elements and Compounds in Everyday Life

• Silver and gold are used to make jewellery
• Oxygen is used in hospitals to help patients with breathing problems
• Carbon in the form of graphite is used to make pencils
• Sodium chloride (table salt) is used as a food additive
• Neon is used to make advertisements and lights
• Fluorine is used in making toothpaste for oral hygiene
• Copper is used to make electrical cables
• Iron is used to make items such as nails, roofing sheets, and farm tools
• Potassium and sodium are used to make fertilizer

Mineral Elements

• Elements found in the soil or in food are called mineral elements
• Mineral elements help plants and animals to grow and function properly

Atomic Number and Mass Number

• Atomic number refers to the number of protons in an atom of an element
• Mass number is the sum of protons and neutrons in an atom
• The atomic number is written as a subscript, and the mass number is a superscript
• Both the atomic number and mass number are written on the left side of the symbol of the element
• The number of protons in an atom is equal to the number of electrons in the atom
• The atomic number helps to represent an atom and is called an atomic representation

Examples of Elements

• Hydrogen: symbol - H, atomic number - 1, mass number - 1
• Lithium: symbol - Li, atomic number - 3, mass number - 7
• Lithium has 3 protons and 4 neutrons, therefore the mass number of lithium is 3 + 4 = 7