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Nostrana [21]
3 years ago
9

____________  was the first chemist to organize elements by atomic number

Chemistry
1 answer:
Natalija [7]3 years ago
4 0

Answer:

Henry Moseley

Explanation: Passed with 98

You might be interested in
Francium is an extremely rare alkali metal, many of whose physical properties
bazaltina [42]

Answer:

136 neutrons

87 protons

Explanation:

A neutral atom have equal number of protons and neutrons. In other words we can say that negative and positive charges are equal in magnitude and cancel the each other. For example if neutral atom has 6 protons than it must have 6 electrons.  The number of protons or number of electrons are the atomic number of an atom while the number of protons and number of neutrons are the mass number of an atom. Every atom consist of nucleus or a positive center. The protons and neutrons are present with in the nucleus while electrons are present out side the nucleus. All these three subatomic particles construct an atom.

Example:

In Francium the number of proton and neutron can be found by subtracting the atomic number of francium from its atomic mass. The atomic number will be the number of protons and remaining will show the total number of neutrons present in  nucleus.

Atomic number is 87

Atomic mass 223

223- 87 = 136

So number of neutrons are 136 and number of protons are 87.

6 0
3 years ago
Sarin is a deadly nerve gas that was outlawed by the Chemical Weapons Convention of 1993. However, it has been used at various t
PIT_PIT [208]

Answer:

The correct answer is - a.  Fluorine is the leaving group in Sarin.

Explanation:

A leaving group is a group that leaves a complete negative charge in heterolytic cleavage when it separates out from the molecule. Sarine reacts with the active site of the enzyme acetylcholinesterase that is essential for nerve transmission.

 In this given case, Sarin that is an acid fluoride and ester of methyl phosphonic acid, the fluorine atom is present is the one that leaves with a complete negative charge, therefore, fluorine is the leaving group in Sarin.

Thus, the first option is correct that Fluorine is the leaving group in Sarin.

6 0
3 years ago
which term describes an educated guess based on observation and background research of a topic? a. conclusion b. hypothesis c. l
strojnjashka [21]
It is either a or b. Hope this helps...
5 0
4 years ago
Read 2 more answers
4.305 liters to microliters
Hatshy [7]

4.305 L = 4.305 × 10^6 µL

1 µL = 10^(-6) L

∴ 4.305 L × [1 µL/10^(-6) L] = 4.305 × 10^6 µL

6 0
3 years ago
Name two fluid technologies that make use of air
nika2105 [10]

Answer: Refrigerator and fire extinguisher

Explanation: Refrigerator:An evaporator fan draws air from the refrigerator and blows it over the evaporator coils. The liquid refrigerant absorbs heat from the air and the air blows back into the refrigerator at a lower temperature, cooling the refrigerator. The liquid refrigerant starts to vaporize as it heats up and moves to the compressor.

Fire extinguisher:They work by smothering the fire: when you put a layer of powder or foam on the fire, you cut the fuel off from the oxygen around it, and the fire goes out. Carbon dioxide (CO2) extinguishers contain a mixture of liquid and gaseous carbon dioxide (a nonflammable gas).

7 0
3 years ago
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