Answer:
Explanation:
uestion
If an atom of an element has a mass number of 45 and it has 20 neutrons in its nucleus, what is the atomic number of the
element?
Tataattatataaggagahahah( to answer it)
9. A
10. C
Answer:
-) Oxidizing agent: 
-) Reducing agent: 
Explanation:
The first step is separate the reaction into the <u>semireactions</u>:
A.
B.
If we want to balance in <u>basic medium </u>we have to follow the rules:
1. We adjust the oxygen with 
2. We adjust the H with 
3. We adjust the charge with 
Lets balance the first semireaction A. :
Now, lets balance semireaction B:
Finally, we have to add the two semireactions:
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Cancel out the species on both sides:
Simplifying the equation :
The is <u>oxidized</u> therefefore is the <u>reducing agent</u>. The is<u> reduced</u> therefore is the <u>oxidizing agent</u>.
Molality= moles NaCl/ Kg H2O
250 g (1 Kg/ 1000 grams)= 0.250 Kg
Molality= 0.611 moles/ 0.250 Kg= 2.44 molal
Answer:
1. Heterogeneous: Mixtures in which composition is not uniform throughout. For example, soil.
2. Homogeneous: Mixtures that have uniform composition throughout. For example, air.
3. Solute: the component of a solution which is present in smaller quantity. For example, Sugar in water
4. Solvent: the component of a solution which is pr3esent in larger quantity. For example, water
5. Solution: A solution is a homogeneous mixture of two or more substances. For example brass.
6. Mixture: When two or more compounds or elements mix up physically they from a mixture.
7. Colloid: Solutions in which particles are large and possess the characteristics of the Tyndall effect. For example milk.
8. Dissociation: the splitting of a molecule into smaller molecules is called dissociation.
9. Pure substance: A pure substance is a type of matter having definite properties.
10. Suspension: Suspensions are heterogeneous mixtures of undissolved particles. For example milk of magnesia.
11. Element: element is a substance made up of the same number of atoms.For example hydrogen
12. Compound: Compound is a substance made up of two or more elements. For example water.
