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: 1. HYDROCARBONS? 2. ALKANES?
i'm not exactly AMAZING at this but i did some research and this is what i think it is i'm also not in this grade but i tried.
Answer:
d. compound
Explanation:
<u>Mixture </u>: It is defined as the substance that is made by the combination of two or more different components which are physically combined.
<u>Homogeneous mixture</u> are the mixtures in which the composition of the substances in it are uniformly mixed. <u>Heterogeneous mixture</u> are the mixtures in which the composition of the substances in it are not uniformly mixed.
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Compound :</u> It is a pure substance which is made from atoms of different elements combined together in a fixed ratio by mass and are chemically bonded.
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Element :</u> It is a pure substance which is composed of atoms of similar elements.
<u>As discussed above, The different elements in the compounds are chemically bonded and hence, it is the substance which can be broken down into the simpler units when it subtend only by the chemical change.</u>
Explanation:
Ok so water is H2O and cabon dioxide in the air is CO2, so the water goes through the carbon dioxide and makes acid rain H2SO4.
Now we have our limestone which is CaCO3.
What happens is that the acid breaks apart our limestone into Ca2+ and CO3 2-. This then reforms into Calcium bicarbonate Ca(CO3)2.
Calcium bicarbonate is soluble in water and is hence washed away by the rain eroding the limestone.