Answer:
Option A - nucleus
Explanation:
A molecule is formed when two or more atoms join together chemically. If atoms combine that are of two or more different elements, we call that a compound. All compounds are molecules, but not all molecules are compounds.
Combustion involves with heat. The answer is burning wood.
Answer:
Explanation
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One
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Ca(OH)2 + 2HNO3 -----> Ca(NO3)2 + H2O
Focus on the NO3. This is an odd problem and you usually do not focus on the complex ion. But this one works easiest if you do.
The problem now is going to be the oxygens. There are 2 with the Calcium and only 1 free one going to the water. (The NO3 has been taken care of in the last step).
Ca(OH)2 + 2HNO3 -----> Ca(NO3)2 + 2H2O
Count the atoms. I think this equation is balanced.
atom Left Right Result
Ca 1 1 Balanced
O 8 8 Balanced
H 2 + 2 2*2 Balanced
N 2 2 Balanced
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Two
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CH4 + O2====> CO2 + H2O
Start with the hydrogens.
The right side requires a 2
CH4 + O2 ===> CO2 + 2H2O
Now look at the oxygens. There are 4 on the right. and only 2 on the left. You need to multiply O2 by 2
CH4 + 2O2 ===> CO2 + 2H2O
Each side has 1 Carbon 4 hydrogens and 4 oxygens. The equation is balanced.
1. 2CaS + 2H2O --> Ca(HS)^2 + Ca(OH)^2
2. Au^2S^3 + 3H2 --> 2Au + 3H2S
4:2. You are comparing the coefficients of NH3 and N2
