Answer:
ice forming and then melting back into water
The correct answer is 10 billion years. The Sun is expected to undergo hydrogen fusion for a total of 10 billion years. The Sun generates its energy by nuclear fusion of hydrogen and produces helium nucleus. It fuses 620 million metric tons every second.
Answer:
Matter is anything that has mass
Explanation:
The word "matter" refers to anything that has mass, either organic or inorganic. Matter is made up of atoms, which consists of a nucleus (made up of protons, positively charged, and neutrons, electrically neutron) and electrons which revolve around the nucleus.
The number of protons in the atom determine the element: there are more than 100 different elements in nature, with different properties depending on the number of electrons they have.
Matter can be in three different states also:
- solid: the atoms are tightly bond to each other, so they cannot move
- liquids: atoms are not bond to each other, so they can slide past each other, but still they have some intermolecular forces that keep them close to each other
- gas: atoms are free to move, as there are no forces that keep them close to each other
