<u>Answer:</u> The original element is
<u>Explanation:</u>
Alpha decay is defined as the process in which alpha particle is emitted. In this process, a heavier nuclei decays into a lighter nuclei. The alpha particle released carries a charge of +2 units.
The released alpha particle is also known as helium nucleus.
For the given alpha decay process of an isotope:
<u>To calculate A:</u>
Total mass on reactant side = total mass on product side
A = 208 + 4
A = 212
<u>To calculate Z:</u>
Total atomic number on reactant side = total atomic number on product side
Z = 82 + 2
Z = 84
The isotopic symbol of unknown element is
Hence, the original element is
I found the rest of the exercise on the internet and these are the options.
"-Undifferentiated vertebrae throughout the body.
-One neck vertebra allowing up and down movement.
-Many neck vertebrae that allow for greater mobility.
<span>-Two neck vertebrae allowing up and down and sideways movement."
The correct answer would be the third. - "</span>Many neck vertebrae that allow for greater mobility." The <span>present-day organism with four limbs has a neck with several vertebrae that allow movements of rotation (mostly because of only two vertebrae at the top of the neck), and side way movements, as well as back and forth movements.</span>
Space between particles tend to increase during the application of heat or heating.
Answer:
1. increase the temperature
2. increase the concentration of reactants
3. increase the surface area of the reactants
4. use a catalyst
5. remove the product as it's formed
Explanation:
for a chemical reaction to take place, the bonds between atoms in the reactants are broken, the atoms rearrange and new bonds between the atoms are formed to make the products.
Answer:
1s² 2s² 2p⁵
Explanation:
The elements of group 17 are called halogens. These are six elements Fluorine, Chlorine, Bromine, Iodine, Astatine. Halogens are very reactive these elements can not be found free in nature. Their chemical properties are resemble greatly with each other. As we move down the group in periodic table size of halogens increases that's way fluorine is smaller in size as compared to other halogens elements. Their boiling points also increases down the group which changes their physical states. i.e fluorine is gas while iodine is solid.
Properties of fluorine:
1. it is yellow in color.
2. it is flammable gas.
3. it is highly corrosive.
4. fluorine has pungent smell.
5. its reactions with all other elements are very vigorous except neon, oxygen, krypton and helium.
6. Its atomic number of 9.
7. its atomic mass is 18.99 amu.
Electronic configuration:
₉F = 1s² 2s² 2p⁵