Chemistry quiz

More questions about Chemistry

These visible examples show the question style. LearnClash turns the full topic into ranked duels and spaced repetition.

1. 1 Easy

   What chart arranges all the chemical elements?

   Answer: Periodic table

   Why: Mendeleev's 1869 table listed the 63 elements then known and left gaps; gallium, scandium and germanium later filled them, and by 2016 the table held 118.

2. 2 Medium

   Where was helium first discovered?

   Answer: The Sun

   Why: A yellow line in the Sun's spectrum revealed helium in 1868; it was named after Helios and only found on Earth 27 years later.

3. 3 Hard

   Which solid element has the lowest density at room temperature?

   Answer: Lithium

   Why: At 0.534 grams per cubic centimetre lithium floats on water, and it is one of only three elements forged in the Big Bang.

4. 4 Easy

   Where in an atom are protons and neutrons located?

   Answer: Nucleus

   Why: Although the nucleus holds over 99.9% of an atom's mass, it takes up almost none of the atom's volume.

5. 5 Medium

   Who discovered the existence of the atomic nucleus in 1911?

   Answer: Ernest Rutherford

   Why: He expected the particles to sail through and found a few bouncing straight back, which he compared to a shell rebounding off tissue paper.

6. 6 Hard

   From what substance did Hennig Brand first isolate phosphorus?

   Answer: Urine

   Why: In 1669 Brand boiled down about 5,700 litres of urine and got just 120 grams of a waxy solid that glowed in the dark.