Learn about the classification of matter based on whether the chemical composition is pure or a mixture. Understand the definitions of elements, compounds, substances, and mixtures, and what the differences are between them. Five types of mixtures are explained, and the symbols used to represent elements in chemical formulae.
Looks at the two categories of natural resources, what they are used for, their distribution around the world, threats to natural resources, recycling and composting, and conservation.
The basics of how humans reproduce is covered here. Learn about female and male reproductive organs, mating, fertilization, how a fetus develops, and birth.
Sickle cell disease is an inherited blood disorder. Learn what it is and how it is passed on, what sickle cell crisis is and its cause, the signs and symptoms of sickle cell disease, how it is treated, tips for traveling if you have it, and how to manage the disease and care for oneself.
Learn about the different stages of the Earth's water cycle, and about processes involving water, including runoff, infiltration, and the differences between hard and soft water.