They were Native Americans.
If you're looking for "what rocks are formed by changes..." it's Igneous Rocks.
Answer is: <span>excited state.
In </span>excited state, hydrogen has<span> higher </span>energy<span> than in the </span>ground state (state with lowest energy). H<span>ydrogen atom has one </span>electron<span> in the lowest possible </span>orbit<span> (1s), when atom absorbs</span><span> energy</span><span>, the electron move into an excited state (quantum numbers greater than the minimum possible). </span>Electron lifetime in excited state is short.
Answer:
D
Explanation:
( I hope that this helps )
Answer:
B. 0.2.
Explanation:
<em>n = mass/molar mass</em>
mass of CaCO₃ = 20 g, molar mass of CaCO₃ = 100.0869 g/mol.
<em>∴ n = mass/molar mass = </em>(20 g)/(100.0869 g/mol) <em>= 0.1998 ≅ 0.2 mol.</em>
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<em>So, the right choice is: B. 0.2.</em>
