It's B Covalent.Now I'll add more words since the thing says I need to write at least 20 characters.
Answer:
<em>O</em><em>r</em><em>g</em><em>a</em><em>n</em><em>i</em><em>s</em><em>m</em><em> </em><em>,</em><em> </em><em>P</em><em>o</em><em>p</em><em>u</em><em>l</em><em>a</em><em>t</em><em>i</em><em>o</em><em>n</em><em> </em><em>,</em><em> </em><em>C</em><em>o</em><em>m</em><em>m</em><em>u</em><em>n</em><em>i</em><em>t</em><em>y</em><em> </em><em>,</em><em> </em><em>E</em><em>c</em><em>o</em><em>s</em><em>y</em><em>s</em><em>t</em><em>e</em><em>m</em><em> </em><em>.</em>
Explanation:
<u>Organism</u> is one type of species .
<u>Population</u> is a group of same species living together .
<u>Community</u> is a group of different species living together .
<u>Ecosystem</u> is a large group of community of species and its environment consisting of biotic and abiotic factor .
Answer:
Divide the mass of the compound in grams by the molar mass you just calculated. The answer is the number of moles of that mass of compound
Explanation:
The Cambrian period I think
Answer: Vibråtory movement.
Explanation: when particles bounce against each other the friction creates thermal energy. Think about what happens when you rub your hands together and they get warmer, that the friction between your hands making thermal energy.