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3 years ago

How should a stopper be handled after is has been removed from a reagent bottle?

1 answer:

6 0

<span>The stopper should be held until it can be safely re-inserted. Placing it on any other type of surface or table could run the risk of cross-contamination. This could cause issues with the reagent when the stopper is replaced.</span>

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6th grade science . :((

Nadusha1986 [10]

Answer:

C- private

Explanation:

This event seems to be exclusive. That is why it is private.

3 0

3 years ago

In 1911, Ernest Rutherford tested the atomic model existing at the time by shooting a beam of alpha particles (42He, helium nucl

STatiana [176]

Answer:

At the time of Rutherford's experiment, the accepted model for the atom was the Thomson plum-pudding model of the atom, in which the atom consists of a "sphere" of positive charge distributed all over the sphere, with tiny negative particles (the electrons) inside this sphere.

In his experiment, Rutherford shot alpha particles towards a very thin sheet of gold foil. He observed the following things:

1- Most of the alpha particles went undeflected, but

2- Some of them were scattered at very large angles

3- A few of them were even reflected back to their original directions

Observations 2) and 3) were incompatible with Thomson model of the atom: in fact, if this model was true, all the alpha particle should have gone undeflected, or scattered at very small angles. Instead, due to observations 2) and 3), it was clear that:

- The positive charge of the atom was all concentred in a tiny nucleus

- Most of the mass of the atom was also concentrated in the nucleus

So, Rutherford experiment lead to a change in the atomic model of the atom, as it was clear that the plum-pudding model was no longer adequate to describe the results of Rutherford's experiment.

5 0

3 years ago

How many grams are in 1.946 moles of nacl

Ilia_Sergeevich [38]

Answer:

113.8g

Explanation:

Statement of problem: mass of 1.946mole of NaCl

Given parameters:

Number of moles of NaCl = 1.946mole

Unknown: mass of NaCl

Solution

To find the mass of NaCl, we apply the concept of moles which expresses the relationship between number of moles and mass according to the equation below:

Number of moles = $\frac{mass}{molar mass}$

To find the molar mass of NaCl:

the atomic mass of Na = 23g

atomic mass of Cl = 35.5g

Molar mass of NaCl = (23 + 35.5) = 58.5gmol⁻¹

Mass of NaCl = Number of moles x molar mass of NaCl

Mass of NaCl = 1.946 x 58.5 = 113.8g

7 0

3 years ago

What do all electrolytes have in common?

Lerok [7]

Your answer would be they have mobile ions in solution.

7 0

3 years ago

What is the total number of atoms in a 75 g sample of zinc?

velikii [3]

Jinx kxknxbxbxbjxj dbdbcj

8 0

3 years ago