Chemistry Quiz: Symbols and Formulae

What does the chemical symbol 'H' represent?

• Helium

• Hydrogen

• Hafnium

• Holmium

Answer explanation

The chemical symbol 'H' represents Hydrogen, the first element on the periodic table. Helium (He), Hafnium (Hf), and Holmium (Ho) have different symbols, making Hydrogen the correct choice.

Which of the following is a compound?

• Hydrogen

• Water

• Iron

• Oxygen

Answer explanation

Water is a compound made up of two hydrogen atoms and one oxygen atom (H2O). In contrast, hydrogen, iron, and oxygen are elements, not compounds.

What is the formula for carbon dioxide?

• C₂O₂

• CO

• CO₂

• C₂O

Answer explanation

The formula for carbon dioxide is CO₂, which consists of one carbon atom and two oxygen atoms. The other options do not represent carbon dioxide correctly.

Which element has the symbol 'Fe'?

• Francium

• Iron

• Fluorine

• Fermium

Answer explanation

The symbol 'Fe' stands for Iron, derived from its Latin name 'ferrum'. Francium, Fluorine, and Fermium have different symbols: Fr, F, andFm respectively.

What does the subscript in a chemical formula indicate?

• The charge of the atom

• The type of element

• The number of atoms

• The state of matter

Answer explanation

The subscript in a chemical formula indicates the number of atoms of the element present in the compound. For example, in H2O, the '2' indicates there are two hydrogen atoms.

Which of the following elements is represented by the symbol 'O'?

• Osmium

• Oxygen

• Oganesson

• Oganes

Answer explanation

The symbol 'O' represents Oxygen, which is a vital element for life and is essential for respiration. Osmium and Oganesson are represented by 'Os' and 'Og', respectively, while 'Oganes' is not a recognized element.

What is the chemical formula for sulfuric acid?

• H₂O

• H₂S

• H₂SO₄

• H₂SO₃

Answer explanation

The chemical formula for sulfuric acid is H₂SO₄, which consists of two hydrogen (H) atoms, one sulfur (S) atom, and four oxygen (O) atoms. The other options represent different compounds.

Which two letters do not appear on the periodic table?

• Q and J

• A and B

• X and Y

• Z and W

Answer explanation

The letters Q and J do not represent any elements on the periodic table. All other letters in the answer choices correspond to at least one element, making Q and J the correct answer.

What is the chemical symbol for magnesium?

• Mn

• M

• Mg₂

• Mg

Answer explanation

The chemical symbol for magnesium is 'Mg'. The other options, 'Mn' (manganese), 'M' (not a valid symbol), and 'Mg₂' (incorrect format), do not represent magnesium. Therefore, 'Mg' is the correct choice.

What does the formula H₂O represent?

• Water

• Hydrogen gas

• Oxygen gas

• Hydrogen peroxide

Answer explanation

The formula H₂O represents water, which consists of two hydrogen atoms bonded to one oxygen atom. This distinguishes it from hydrogen gas (H₂), oxygen gas (O₂), and hydrogen peroxide (H₂O₂).