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3 years ago

PLZZZZ NEEDDD HELPPPO‼️‼️

Chemistry

1 answer:

svlad2 [7]3 years ago

7 0

Answer:

1.) When Mendeleev arranged the elements in order of increasing atomic mass, the properties where repeated. Because the properties repeated themselves regularly, or periodically

2.) i can't really answer this one because it's not a direct question but if you get your periodic table and look at the list that it gave you look at which elements are in the same row and you you will get the correct answer that way

3.) and this question is referring back to question two so just pick one of the idem ( this means chose a name of an element) alkali elements and say because you mixed up alkaline and alkali and you figured it out by remembering what group and what row it was in

4.) name an element that can't be put into one group and chose this from the alkali group

5.) the number of valence electrons stays the same as you go up or down a group, but they increase as you go from left to right across the periodic table.

6.) sorry i don't really know how to explain this one

Explanation:

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What type of charge do electrons have?

schepotkina [342]

Answer:

negative charge

Explanation:

Neutrons have no charge, protons have positive charge, and electrons have a negative charge

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2 years ago

Sắp xếp các hợp chất: HF, HI, HBr, HCl theo chiều giảm dần tính axit.

mixer [17]

I don’t know what to answer

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2 years ago

The length of a vector arrow represents its magnitude and the point represents its direction

Viefleur [7K]

The answer is: True.

The magnitude of a vector is represented by the length of the arrow.

The arrow length is drawn according a chosen scale.

For example, the diagram shows a vector with a magnitude of 100 kilometers, if the scale used for constructing the diagram is 1 cm = 10 km, the vector arrow is drawn with a length of 10 cm.

The arrow has an obvious tail and arrowhead. The arrow points in the precise direction.

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3 years ago

Read 2 more answers

purification of chromium can be achieved by electrorefining chromium from an impure chromium anode onto a pure chromium cathode

stiv31 [10]

The chromium in the electrolytic solution is present as cr³⁺ will take 6.19 hours will it take to plate 18.0 kg of chromium onto the cathode if the current passed through the cell is held constant at 45.0 A.

It is given that mass is 18 kg. Converting mass into grams

18 x (1000g / 1 kg)

= 18000 g

So, 18 kg = 18000 g

Now, calculate the number of moles

No. of moles = mass of Cr / molecular mass of Cr

No. of moles = 18000 / 52 g/mole

No. of moles = 346.15 mole

For , Cr³⁺, 3 moles of electrons are required

Hence,

3 x 346.15 mole

1038.45

As 96500 C of charge are present in 1 mole of electrons. As a result, the charge held by 1038.45 mole of electrons will be determined as follows.

= 1038.45mol x 96500 C / mole

= 10.02 x 10⁷ C

As, we know that relation between charge, current and time is as follows.

Q = I x T

Current is given as 45 A

Therefore, charge is calculated

T = Q / I

T = 100.21 x 10⁶ / 45

T = 2.227 x 10⁶

As there are 3600 seconds in one 1 hour. Converting 2.227 x 10⁶ into hours are

= 2.227 x 10⁶ / 3600 sec/h

= 6.19 hours

Thus, if the current flowing through the cell is maintained constant at 45 A, we may estimate that it will take 6.19 hours to plate 18 kg of chromium onto the cathode.

To know more about electrolytic solution visit :

brainly.com/question/9203208

#SPJ4

4 0

1 year ago

The equilibrium constant for the reaction

Hitman42 [59]

The question is incomplete, here is the complete question:

The equilibrium constant for the reaction

N₂O₄(g)⇌2NO₂ at 2°C is Kc = 2.0

If each yellow sphere represents 1 mol of N₂O₄(g) and each gray sphere 1 mol of NO₂ which of the following 1.0 L containers represents the equilibrium mixture at 2°C?

The image is attached below.

Answer: The system which represents the equilibrium having value of $K_c=2.0$ is system (b)

Explanation:

Equilibrium constant in terms of concentration is defined as the ratio of concentration of products to the concentration of reactants each raised to the power their stoichiometric ratios. It is expressed as $K_c$