When I celebrated my bar mitzvah, there was no cake. Today, there is no such thing as a bar mitzvah in the United States without a special cake. It can be even more complicated and expensive than a wedding cake, because bar-mitzvah cakes are often based on a particular theme.
Some plants are carnivores, gaining nutrients by eating various small insects and spiders. A well known example of a carnivorous plant is the Venus Flytrap.
Alkali metals such as sodium, potassium, rubidium, caesium and francium are extremely reactive elements, just putting them in water can result in an explosion! They are carefully stored in oil to prevent this happening.
While aluminum is the most common metal found in the Earth's crust, the most common metal found on Earth is iron, mostly because it makes up such a large part of the Earth's core.
