Hypothesis: All birds can fly
Counterexample: Penguins
Counterexample: Penguins
Hypothesis: All triangles have equal sides.
Counterexample: Scalene triangles have sides of different lengths.
Counterexample: Scalene triangles have sides of different lengths.
Hypothesis: All even numbers are divisible by 4.
Counterexample: 6 is an even number but is not divisible by 4.
Counterexample: 6 is an even number but is not divisible by 4.
Hypothesis: All prime numbers are odd.
Counterexample: 2 is a prime number and is even.
Counterexample: 2 is a prime number and is even.
Hypothesis: All liquids freeze at 0 degrees Celsius.
Counterexample: The freezing point of Mercury is about -38.83 degrees Celsius.
Counterexample: The freezing point of Mercury is about -38.83 degrees Celsius.
Hypothesis: All thunderstorms produce lightning.
Counterexample: Some thunderstorms do not produce lightning.
Counterexample: Some thunderstorms do not produce lightning.
Hypothesis: All deserts are hot.
Counterexample: Antarctica is a cold desert.
Counterexample: Antarctica is a cold desert.
Hypothesis: All wood floats in water.
Counterexample: Ebony wood is dense and sinks in water.
Counterexample: Ebony wood is dense and sinks in water.
Hypothesis: All fruits are sweet.
Counterexample: Lemons are fruits but are sour.
Counterexample: Lemons are fruits but are sour.
Hypothesis: All flowers are brightly colored.
Counterexample: Bat flowers are a dark color close to black.
Counterexample: Bat flowers are a dark color close to black.
Hypothesis: All liquids evaporate at the same rate.
Counterexample: Water evaporates faster than honey.
Counterexample: Water evaporates faster than honey.