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3 years ago

Describe Henri Becquerel's role in the discovery of radioactivity

Chemistry

1 answer:

yan [13]3 years ago

8 0

Answer:

Explanation:

In 1896 Henri Becquerel was using naturally fluorescent minerals to study the properties of x-rays, which had been discovered in 1895 by Wilhelm Roentgen.

X-rays are neutral and cannot be bent in a magnetic field. The new radiation was bent by the magnetic field so that the radiation must be charged and different than x-rays.

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4. How many atom are in C3H5(NO3)3

shepuryov [24]

Answer:

carbon = 3

hydrogen=5

nitrogen=3

Oxygen=9

8 0

2 years ago

What happens if you are in a swimming pool and you push a beach ball down with your hands?

Aleksandr-060686 [28]

Answer:

it will float back up because it's not dense enough to go down

7 0

3 years ago

What is the Chemical Formula and Net Ionic Equations for all three solutions.

AlladinOne [14]

Answer:

See answer below

Explanation:

As you are asking for chemical formula and ionic equation, then, I will assume that after the station #3 below, are the solutions you are requiring.

You are also not specifing if you want for example, result of solution 1 + solution 3. If you need that, please post that on another question.

Now for the chemical formula, you need to identify the elements in all 3 solutions, and also the type of compound.

1. Solution 2 Potassium Iodide:

In this case we have Potassium on one side, and Iodine on the other side, the symbol for those are K and l. As Potassium have the +1 oxidation state, cause is the only one that it can have, when it's next to an halide like chlorine or bromine, it will form a binary salt. The halides, usually work with the lowest oxydation state. In the case of Iodide it will be -1, so, the formula will be:

And the net ionic equation will be the chemical equation that shows how the charges and atoms are balanced. In this case it would be:

K⁺ + I⁻ ------> KI

2. Solution 1 and 3, Lead (II) nitrate and Sodium carbonate:

In this case I will work with both, because both of the solution are tertiary compounds. In this cases, we have two tertiary salt, The Sodium symbol is Na, and is working with it oxydation state +1. Carbonate is an anion and have the formula CO₃ working with the oxydation state -2. Lead can work with oxidation state +2 and +4. It's symbol is Pb. Nitrate is NO₃ and works with oxydation state -1 instead.

The chemical formula and ionic equation for both will be:

Lead(II) nitrate: Pb(NO₃)₂

Sodium Carbonate: Na₂CO₃

And the net equations:

Lead nitrate: Pb²⁺ + 2NO₃⁻ ------> Pb(NO₃)₂

Copper sulfate: 2Na⁺ + CO₃²⁻ -------> Na₂CO₃

Hope this helps

6 0

3 years ago

In the early twentieth century, what was Alexander Fleming’s hypothesis concerning the relationship between a yellow-green mold

SpyIntel [72]

Answer:

The correct answer is the option c)He thought the mold had released a chemical that prevented the bacteria’s growth.

Explanation:

In the 1920s, Alexander Fleming was working in his laboratory at St. Mary's Hospital in London when, almost by accident, he discovered a naturally growing substance that could attack certain bacteria. In one of his experiments, Fleming observed that colonies of a bacterium had been depleted or removed by a mold that grew on the same Petri dish. He observed that the bacteria furthest from the fungus had grown to produce large-sized colonies, while the colonies closest to the fungus were tiny. He determined that mold made a substance that could dissolve bacteria. The fungus was penicilium chrysogenum and thus Fleming called this substance penicillin, by the name of the mold that produces it. Thus, after several years of experiments in 1930, Howard Florey and Ernest Chain developed at Oxford University the procedures to produce pure penicillin from the fungus that Fleming isolated. Thus penicillin could be concentrated by Florey and Chain, and in 1945 they shared with Fleming the Nobel Prize in Medicine.

Then, the correct answer is the option c)He thought the mold had released a chemical that prevented the bacteria’s growth.

4 0

3 years ago

10g of a non-volatile and non-dissociating solute is dissolved in 200g of benzene.

ehidna [41]

Answer: The molar mass of solute is 115 g/mol.

Explanation:

Elevation in the boiling point is defined as the difference between the boiling point of the solution and the boiling point of the pure solvent.

The expression for the calculation of elevation in boiling point is:

$\text{Boiling point of solution}-\text{boiling point of pure solvent}=i\times K_b\times m$

$\text{Boiling point of solution}-\text{Boiling point of pure solvent}=i\times K_f\times \frac{m_{solute}\times 1000}{M_{solute}\times w_{solvent}\text{(in g)}}$ ......(1)

where,

Boiling point of pure solvent (benzene) = $80.10^oC$

Boiling point of solution = $81.20^oC$

i = Vant Hoff factor = 1 (for non-electrolytes)

$K_b$ = Boiling point elevation constant = $2.53^oC/m$

$m_{solute}$ = Given mass of solute = 10 g

$M_{solute}$ = Molar mass of solute = ? g/mol

$w_{solvent}$ = Mass of solvent = 200 g

Putting values in equation 1, we get:

$81.20-80.10=1\times 2.53\times \frac{10\times 1000}{M_{solute}\times 200}\\\\M_{solute}=\frac{1\times 2.53\times 10\times 1000}{1.1\times 200}\\\\M_{solute}=115g/mol$

Hence, the molar mass of solute is 115 g/mol.

4 0

3 years ago