Science Facts Set-12

• The age of the Earth is around 4.5 billion years.
• Antibiotics are substances that kill or inhibit the growth of bacteria.
• Yuri Gagarin is the first human in outer space.
• Viruses are active only when they are in their host organisms.
• There are about 50 species of rats on Earth.

• Osmium is the densest natural element. 
• The mean distance between the Earth and the Sun is one Astronomical Unit (AU). One AU is equal to 149,598,000 kilometres. 
• Valentina Tereshkova is the first woman in outer space. 
• The components of blood are classified into liquid component-Plasma and Solid component-corpuscles. 
• Gold is a metal which does not react with steam.