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ENERGY: Action of electricity on materials
ENERGY: Action of heat on materials
MATTER - PROPERTIES AND TRANSFORMATION: Chemical Reactions And Equations
MATTER - PROPERTIES AND TRANSFORMATION: Chemical Symbols, Formulae And Valency
MATTER - PROPERTIES AND TRANSFORMATION: Effect Of Heat On Substances
MATTER - PROPERTIES AND TRANSFORMATION: Introduction To Chemistry - Symbols
MATTER - PROPERTIES AND TRANSFORMATION: Mixtures And Pure Substances
MATTER - PROPERTIES AND TRANSFORMATION: Periodic table - Families of elements and Relative reactivity
MATTER - PROPERTIES AND TRANSFORMATION: Reaction With Oxygen of air
MATTER - PROPERTIES AND TRANSFORMATION: The Atom And Sub-Atomic Particles
5/70 MCQs for:
MATTER - PROPERTIES AND TRANSFORMATION: Periodic table - Families of elements and Relative reactivity
Why did Mendeleev leave gaps in his periodic table?
He ran out of elements to classify.
He made errors in his calculations.
He wanted to make the table look balanced.
He believed there were elements yet to be discovered.
Why is Hydrogen sometimes placed separately from Group 1 elements?
It's a non-metal with unique properties.
It's radioactive.
It's a noble gas.
It has no protons.
Which pair of elements from the first 20 elements would you expect to have similar chemical properties?
Hydrogen and Helium.
Carbon and Nitrogen.
Sodium and Magnesium.
Oxygen and Sulfur.
How does the metallic character generally change across a period (from left to right) in the periodic table?
Decreases.
Remains the same.
Increases.
Fluctuates randomly.
The first 20 elements of the periodic table cover how many periods?
6 periods.
4 periods.
5 periods.
3 periods.
