CHEMISTRY HIGH SCHOOL

Mendeleev’s principle of chemical periodicity states that when the elements are arranged according to their atomic numbers. This periodic law allows elements with similar properties to appear at regular intervals. Predict the group of elements and their number of valence electrons that will combine in a 2:1 ratio to with sodium. A)bromine, chlorine, iodine, 7
B)
sulfur, selenium, polonium, 6
Eliminate
C)
hydrogen, fluorine, potassium, 1
D)
calcium, phosphorus, tellurium, 2

Answers

Answer 1
Answer:

The correct option is B.

Sodium will react with elements in GROUP 6, WHICH HAVE SIX ELECTRONS IN THEIR OUTERMOST SHELLS.

Sodium is a metal with atomic number 11. The electronic configuration of sodium is 2,8,1. This implies that, sodium has one electron in its outermost shell. Sodium always donate this electron in order to become stable. Elements in group 6 have six electrons in their outermost shells and they require two more electrons to attain stability. In order to form chemical bonds with elements from group 6, two atoms of sodium will react with each atom of those elements, that is, the ratio of reaction will be 2:1. By so doing, the two sodium atoms will be the ones that will donate the two electrons that the group 6 elements need to attain stability. One example of compounds formed by such reaction is sodium sulfide, Na2S.

Answer 2
Answer: The main part of this question is the "2:1 ratio."

On the periodic table, bromine, chlorine, and iodine have 7 valence electrons and sulfur, selenium, and polonium have 6, so these choices are viable based on their valence electrons. However, fluorine does not have 1 valence electron and phosphorus and tellurium do not have 2 valence electrons, so C) and D) are automatically out, leaving A) and B).

If we know that the sodium will combine in a 2:1 ratio, we know that the charge of the ions must have a 2:1 ratio too; that's how ionic compounds work. Sodium (Na) has an ion with a charge of +1 (Na+), so that means whatever ion it combines with in a 2:1 ratio must have a charge of -2   -   a 2:1 ratio.

Bromine, chlorine, and iodine have a charge of -1, but sulfur, selenium, and polonium have charges of -2. This gives us the correct answer as C).

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Can someone how to do these problems!!
A salt is best described as a compound that is formed from the reaction betweenan acid and a base.a strong acid and a weak acid.a strong base and a weak base.an acid and water.

Hich element is likely to be the most brittle?a. selenium
b. cobalt
c. platinum
d. zinc

Answers

Answer:

a. Selenium

Explanation:

Hello,

Selenium is a crystalline non-metallic element that has variable properties depending on how it is prepared, but they are all hard solids. Zinc is less brittle than selenium since it has stronger metallic properties. On the other hand, cobalt and platinum are strong metals that are far away to be brittle.

Best regards.
The most brittle one is selenium!

A detailed explanation, one paragraph of the colligative property being discussed and why that property changes the way that it does when the amount of solute is increased. A detailed description, at least one paragraph, of a real-world application of the colligative property, including an explanation of how this application of the colligative property is important or useful to those affected. The real-world example must be one that was not mentioned in the lesson.

Answers


You can do it on the icing of roads, reverse osmosis for desalination of water, dissolved CO2 in soda cans, osmotic pressure involving blood vessels and IV solutions, etc.

What two forces act in the nucleus to create a 'nuclear tug of war'?

Answers

In Nuclei, There are 2 forces. 1 force is electrostatic and acts as repulsion between 2 protons. The other is force of attraction called Nuclear force between 2 neutrons. This nuclear force is a short range force and is so strong that it negates the effect of the force of repulsion between the protons and helps bind the nucleus together. Hope this helped :D

What are the relative ion concentrations in an acid solution?

Answers

Answer is: more H⁺ ions than OH⁻ ions.
An Arrhenius acid is a substance that dissociates in water to form hydrogen ions or protons. 
For example, hydrochloric acid dissociate in aqueous solution to form hydrogen ions (H⁺) and chloride anion (Cl⁻):
HCl(aq) → H⁺(aq) + Cl⁻(aq).

An Arrhenius base is a substance that dissociates in water to form hydroxide ions (OH⁻). 
For example lithium hydroxide is an Arrhenius base:

LiOH(aq) → Li⁺(aq) + OH⁻(aq).

Answer:

more H+ ions

Explanation:

Our body needs iron. Certain foods are rich in iron and iron tablets are usually recommended by doctors. but neither the food nor tablets are hard like iron? Why?

Answers

If the food and the tablets would be hard then how will the body digest it
because it would not be possible to eat them if they would be hard

Bromine, a liquid at room temperature, has a boiling point of 58° C and a melting point of -7.2° C bromine can be classified as a Compound, impure substance, mixture, or pure substance

Answers

The answer to the chemistry question above would be pure substance. Bromine is classified as a pure substance because only the element is present and there are no other substances added or mixed with it. It is also not a compound because it does not come with another element. 

Answer:

pure substance

Explanation:

i just did on edgen
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