Hot air balloons have hot air inside them, which is less dense as the air around it. Thus it rises. A cold air balloon would sink because the air would be more dense than the air around it. Also, the balloon’s volume would vary in size depending on the weight of the balloon.
Answer:
Ionic compounds contain ions and are held together by the attractive forces among the oppositely charged ions
Explanation:
Common salt (sodium chloride) is one of the best-known ionic compounds. Molecular compounds contain discrete molecules, which are held together by sharing electrons (covalent bonding).
Many elements show very strong similarities to each other.<span>For example, lithium (Li), sodium (Na), and potassium (K) are all soft, very reactive metals.
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Alfred Wegner was the first person to propose the idea that all seven continents were all one supercontinent called "Pangea". Everyone considered his theory to be a joke until he found evidence to back up his theory. His evidence was the matching mountain ranges, fossils, certain species, and more over different continents. Also that all the seven continents fit together like puzzle pieces. I hope this helps! :)
