Chemistry Quiz: Elements, the Periodic Table and Reactions

This chemistry quiz covers elements, compounds and the periodic table, with questions on water, hydrogen, pH, Dmitri Mendeleev, the noble gases, table salt, mercury, carbon, iron and the two-time Nobel winner Marie Curie. Ten questions, 90 seconds.

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🎯 Daily Trivia Challenge • 🧠 10 Questions • ⏱️ 90 Seconds

Question 1 / 10 Time: 90s

Compounds
What is the chemical formula for water?
Elements
Which element has the atomic number 1?
Acids and Bases
What is the pH of pure water at room temperature?
Periodic Table
Who published the first widely accepted periodic table in 1869?
Periodic Table
Helium, neon and argon belong to which group of elements?
Compounds
What is the everyday name for sodium chloride, NaCl?
Elements
Which metal is a liquid at room temperature?
Organic Chemistry
Which element is found in all organic compounds?
Scientists
Who was the first person to win Nobel Prizes in two different sciences?
Elements
What is the chemical symbol for iron?

Explanations: answer key for all 10 questions

Q1: What is the chemical formula for water?
Answer: H₂O
Each water molecule has two hydrogen atoms bonded to one oxygen atom. Water is one of the few substances found naturally on Earth as a solid, a liquid and a gas.
Q2: Which element has the atomic number 1?
Answer: Hydrogen
Hydrogen has just one proton and is the lightest and most abundant element in the universe. Stars like the Sun shine by fusing hydrogen into helium.
Q3: What is the pH of pure water at room temperature?
Answer: 7
A pH of 7 is neutral. Lower values are acidic, like lemon juice at about 2, and higher values are alkaline, like soapy water.
Q4: Who published the first widely accepted periodic table in 1869?
Answer: Dmitri Mendeleev
Russian chemist Dmitri Mendeleev arranged the elements by atomic weight and left gaps for elements that had not been discovered yet. Several of his predictions later proved correct.
Q5: Helium, neon and argon belong to which group of elements?
Answer: Noble gases
Noble gases have full outer electron shells, so they rarely react with other elements. Neon glows red-orange in signs when electricity passes through it.
Q6: What is the everyday name for sodium chloride, NaCl?
Answer: Table salt
Sodium is a reactive metal and chlorine a poisonous gas, but together they form harmless table salt. Baking soda is sodium bicarbonate.
Q7: Which metal is a liquid at room temperature?
Answer: Mercury
Mercury melts at about −39 °C, so it is liquid at room temperature. It was once used in thermometers, but it is toxic, so most have been replaced.
Q8: Which element is found in all organic compounds?
Answer: Carbon
Organic chemistry is the chemistry of carbon compounds. Carbon can form four bonds and long chains, which allows the huge variety of molecules that make up living things.
Q9: Who was the first person to win Nobel Prizes in two different sciences?
Answer: Marie Curie
Marie Curie won the Nobel Prize in Physics in 1903 and in Chemistry in 1911, for discovering polonium and radium. Linus Pauling won for chemistry and for peace.
Q10: What is the chemical symbol for iron?
Answer: Fe
Fe comes from ferrum, the Latin word for iron. Ir is iridium and In is indium. Iron is the most common element in Earth by mass.

Chemistry Quiz – The Science of Everything Around You

Chemistry is the study of matter: what things are made of, how they behave and how they change. Every time you cook a meal, light a match, clean with soap or take a medicine, chemistry is at work. Chemists study atoms and molecules to understand why salt dissolves, why iron rusts and why some reactions give off heat.

At the heart of chemistry is the periodic table. In 1869, Dmitri Mendeleev organized the known elements into a table that grouped similar elements together and even predicted elements that had not yet been discovered. Today the table holds 118 elements, from hydrogen, the lightest, to oganesson, the heaviest yet made.

Elements combine to form compounds, often with very different properties. Sodium is a metal that reacts violently with water and chlorine is a toxic gas, yet together they make the salt on your dinner table. Water, made from two gases, is a liquid that covers most of the planet.

Chemistry also has its share of famous scientists. Marie Curie discovered radioactive elements and became the first person to win Nobel Prizes in two sciences, while Antoine Lavoisier is often called the father of modern chemistry for showing that mass is conserved in reactions.

This quiz covers elements, compounds, acids and bases and the history of the periodic table.

What This Quiz Teaches

This quiz suits chemistry students, science teachers and anyone who wants to understand the stuff the world is made of.

What water and table salt are made of
Which element is first on the periodic table
What the pH scale measures
How Mendeleev built the periodic table
Why noble gases rarely react
Why carbon is the basis of life

Quick Facts About Chemistry

Gold is so malleable that one gram can be beaten into a sheet of about one square meter.
Oxygen is the most common element in Earth's crust.
Helium was discovered in the Sun before it was found on Earth.
Dry ice is solid carbon dioxide and turns straight into gas at −78.5 °C.
Tungsten has the highest melting point of any metal, about 3,422 °C.
Only two elements, mercury and bromine, are liquid at standard room temperature.