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 
).
Answer:
In a chemical reaction, reactants that are not used up when the reaction is finished are called excess reagents. The reagent that is completely used up or reacted is called the limiting reagent, because its quantity limits the amount of products formed.
Explanation:
Answer:
stars
earth isn't made of gas. (and you can always see it)
moon us not gas, or give off heat
sun is only visible during the day
Answer:
In atomic physics, the Bohr model or Rutherford–Bohr model, presented by Niels Bohr and Ernest Rutherford in 1913, is a system consisting of a small, dense nucleus surrounded by orbiting electrons—similar to the structure of the Solar System, but with attraction provided by electrostatic forces in place of gravity.
Explanation:
The complete table is inserted.
A table is given,
Formulas used:
pH= -log(H⁺)
pOH= -log(OH⁻)
pH+ pOH=14
Calculations:
For A: (H⁺)=2×10⁻⁸M
Using the pH formula:
pH= -log(H⁺)=-log(2×10⁻⁸)=7.69
pOH=14 - 7.69=6.3
Calculating OH concentration,
pOH= -log(OH⁻)
6.3= -log(OH⁻)
(OH⁻)=5.011×10⁻⁷M
Hence, the nature of A is basic.
Similarily,
For B,
(OH⁻)=1×10⁻⁷
Using the pH formula:
pOH= -log(OH⁻)= -log(1×10⁻⁷)=7
pH=14-7=7
Calculating H concentration,
pH= -log(H⁺)
7= -log(H⁺)
(H⁺)=1×10⁻⁷M
Hence, the nature of B is neutral.
Similarily,
For C,
pH=12.3
Using the pH formula:
pOH=14-12.3=1.7
Calculating H concentration,
pH= -log(H⁺)
12.3= -log(H⁺)
(H⁺)=5.011×10⁻¹³M
Calculating OH concentration,
pOH= -log(OH⁻)
1.7= -log(OH⁻)
(OH⁻)=1.99×10⁻²M
Hence, the nature of C is Basic.
Similarily,
For D,
pOH=6.8
Using the pH formula:
pH=14-6.8=7.2
Calculating H concentration,
pH= -log(H⁺)
7.2= -log(H⁺)
(H⁺)=6.309×10⁻⁸M
Calculating OH concentration,
pOH= -log(OH⁻)
6.8= -log(OH⁻)
(OH⁻)=1.58×10⁻⁷M
Hence, the nature of D is basic.
Learn more about the acid and bases here:
brainly.com/question/16189013
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