Since then, the periodic table has evolved to reflect over 150 years of scientific development and understanding in chemistry and physics. Today, with 118 known elements, it is widely regarded as one ...

Mendeleev made an early periodic table. In the modern periodic table ... Sample questions - Building blocks for understanding - AQA Synergy Understanding how to approach exam questions helps ...

They form coloured compounds and act as catalysts. Sample exam questions - atomic structure and the periodic table - AQA Understanding how to approach exam questions helps to boost exam performance.