Answer:
Hydrogen is placed above group in the periodic table because it has ns1 electron configuration like the alkali metals. However, it varies greatly from the alkali metals as it forms cations (H+) more reluctantly than the other alkali metals.
Explanation:
Answer:
A process during which chemical bonds between atoms are broken and new ones are formed, producing one or more substances.
Moles are the amount of substance that contains as many particles.
Explanation:
A chemical reaction is when a chemical change occurs for example when a nail comes into contact with air and is then exposed to air it begins to rust. It forms a red-brown substance which changes the chemical composition of the original compound.
Examples of chemical reactions:
Combustion
Oxidation (rusting)
Cooking an egg
Photosynthesis
Digestion
Fireworks
Paper Burnin
The mole is the amount of substance that contains as many particles (molecules, ions or atoms) as there are in 12g of carbon.
1 mol is the amount of substance that contains the same number of particles as there are atoms in 12.0 g of carbon-12 and that number is referred to as Avogardo's constant (6.022 x
).
C. a scientific approach to answering questions
The number of formula units in 116 g of NaCl is 1.204×10²⁴ formula units
<h3>Avogadro's hypothesis </h3>
1 mole of NaCl = 6.02×10²³ formula units
But
1 mole of NaCl = 58 g
Thus,
58 g of NaCl = 6.02×10²³ formula units
<h3>How to determine the formula units in 116 g of NaCl</h3>
58 g of NaCl = 6.02×10²³ formula units
Therefore,
116 g of NaCl = (116 × 6.02×10²³) / 58
116 g of NaCl = 1.204×10²⁴ formula units
Thus, 1.204×10²⁴ formula units are present in 116 g of NaCl
Learn more about Avogadro's number:
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<u>Answer:</u> The correct answer is Option D.
<u>Explanation:</u>
Enthalpy change is defined as the difference in enthalpies of all the product and the reactants each multiplied with their respective number of moles. It is represented as 
The equation used to calculate enthalpy change is of a reaction is:
![\Delta H^o_{rxn}=\sum [n\times \Delta H^o_f_{(product)}]-\sum [n\times \Delta H^o_f_{(reactant)}]](https://tex.z-dn.net/?f=%5CDelta%20H%5Eo_%7Brxn%7D%3D%5Csum%20%5Bn%5Ctimes%20%5CDelta%20H%5Eo_f_%7B%28product%29%7D%5D-%5Csum%20%5Bn%5Ctimes%20%5CDelta%20H%5Eo_f_%7B%28reactant%29%7D%5D)
Hence, the correct answer is Option D.