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slega [8]
3 years ago
14

How the model of an atom has changed over time because?

Chemistry
1 answer:
zavuch27 [327]3 years ago
7 0
It was found that atoms are made up of even smaller particles (through experiments), and the models changed because how we thought atoms were composed turned out to be wrong, and corrections were made accordingly.
You might be interested in
How does carbon 14 work
Verdich [7]

Carbon-14 dating is a way of determining the age of certain archeological artifacts of a biological origin up to about 50,000 years old. It is used in dating things such as bone, cloth, wood and plant fibers that were created in the relatively recent past by human activities.

 

6 0
4 years ago
A chemist determines by measurements that 0.030 moles of nitrogen gas participate in a chemical reaction. calculate the mass of
zzz [600]
Remember that: 
number of moles = mass/molar mass

First, we get the molar mass of the nitrogen gas molecule:
It is known the the nitrogen gas is composed of two nitrogen atoms, each with molar mass 14 gm (from the periodic table)
Therefore, molar mass of nitrogen gas = 14 x 2 = 28 gm

Second we calculate the mass of the precipitate:
we have number of moles = 0.03 moles (given)
and molar mass = 28 gm (calculated)
Using the equation mentioned before,
mass = number of moles x molar mass = 0.03 x 28 = 0.84 gm
3 0
3 years ago
Suppose 180 ml of 3.52x10^-4 M NaOH is mixed with 220 mL of 2.47x10^-4 M MgCl2.
velikii [3]
When in water, MgCl2 dissociates into magnesium ions and Cl- ions and NaOH into Na and OH ions. The equation is as follows:

MgCl2 = Mg2+ + 2Cl-
NaOH = Na+ + OH-

The initial concentrations are as follows:

[Mg2+] = .220(<span> 2.47x10^-4) / .220+.180 = 1.36x10^-4 M Mg2+
</span>[OH-] = .180 (3.52x10^-4) / .220+.180 = 1.58x10^-4 M OH-
6 0
3 years ago
Try to make only one molecule of water in the simulation. Is it possible?
mel-nik [20]

Answer:

A single molecule of water has been isolated for the first time by trapping it in a fullerene cage. Water molecules are never found alone — they are always hydrogen-bonded to other molecules of water or polar compounds.

While making small volumes of pure water in a lab is possible, it's not practical to “make” large volumes of water by mixing hydrogen and oxygen together. The reaction is expensive, releases lots of energy, and can cause really massive explosions.

While making small volumes of pure water in a lab is possible, it's not practical to “make” large volumes of water by mixing hydrogen and oxygen together. The reaction is expensive, releases lots of energy, and can cause really massive explosions.

A water molecule consists of three atoms; an oxygen atom and two hydrogen atoms, which are bond together like little magnets. The atoms consist of matter that has a nucleus in the centre. The difference between atoms is expressed by atomic numbers.

Explanation:

3 0
3 years ago
1. Imagine that you need to take a medicine that the doctor has prescribed for you. Explain why scientists who developed that me
ella [17]

Answer: The compound in medicines should be non polar.  

It is important for any drug to be able to dissolve itself through the cell membrane which consists of a lipid bi-layer, in order to diffuse in the body and circulate biologically, performing its function.

Non polar compounds are lipid soluble and therefore can dissolve in the lipid layers.

Polar compounds are water soluble and fail to cross the cell membrane.

Therefore scientists need to be sure of using compounds that are non polar in nature so they pass through the cell membrane and enter into the blood circulation of the body and perform its due function.

Explanation:

6 0
3 years ago
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