Answer:
B
Explanation:
Because the sharpener is attached to an electrical outlet
Quick answer: Exothermic reactions mean that heat has escaped the system. The answer is A. Heat is released.
Valency- it means the combing capacity if an element.
<span> radical- it is an atom, molecule, or ion that has unpaired valence electrons or an open electron shell.
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The formula units in the substances are as follows:
- Br2 = 8.99 × 10^23 formula units
- MgCl2 = 1.51 × 10^24 formula units
- H2O = 2.57 × 10^24 formula units
- Fe = 2.57 × 10^24 formula units
<h3>How many moles are in 239.2 g of the given substances?</h3>
The moles of the substances are determined from their molar mass.
Molar mass of the substances is given as follows:
- Br2 = 160 g/mol
- MgCl2 = 95 g/mol
- H2O = 18 g/mol
- Fe = 56 g/mol
Formula units = mass/molar mass × 6.02 × 10^23
The formula units in the substances are as follows:
- Br2 = 239.2/160 × 6.02 × 10^23 = 8.99 × 10^23 formula units
- MgCl2 = 239.2/95 × 6.02 × 10^23 = 1.51 × 10^24 formula units
- H2O = 239.2/18 × 6.02 × 10^23 = 2.57 × 10^24 formula units
- Fe = 239.2/56 × 6.02 × 10^23 = 2.57 × 10^24 formula units
In conclusion, the number of formula units is derived from the moles and Avogadro number.
Learn more about formula units at: brainly.com/question/24529075
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