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3 years ago

Help plz I'm confused

Chemistry

2 answers:

erik [133]3 years ago

6 0

<u>Answer 45 :</u> This statement is true.

Explanation :

We are taking an example of carbon (C) with atomic number 6 and atomic mass 12.

As we know that the number of protons and number of electrons are equal to the atomic number.

The atomic number of carbon is 6. So, the number of protons and the number of electrons is equal to 6.

And, the number of neutrons = Atomic mass - Atomic number = 12 - 6 = 6

Hence, this statement is true.

<u>Answer 46 :</u> This statement is true.

Explanation :

We are taking an example of oxygen (O) with atomic number 8.

The electronic configuration of oxygen (O) will be,

$1s^22s^22p^4$

Now we have to calculate the number of electrons from the electronic configuration.

The number of electrons = 2 + 2 + 4 = 8

Hence, this statement is true.

9966 [12]3 years ago

6 0

<h2>Answer 1:</h2>

<u>The statement is</u><u> True</u>

<h2>Explanation:</h2>

The number of electrons and protons in any element are the same. Atom as a whole is a neutral particle. Protons are positively charged while electrons are negatively charged. In order to keep the level balanced and keep the atom neutral the net charge must be zero therefore protons and electrons must be the same in order to keep an atom neutral.

<h2>Answer 2:</h2>

<u>The statement is </u><u>True</u>

<h2>Explanation:</h2>

Electron configuration is the distribution of electrons of an atom or molecule or other physical structure in atomic or molecular orbitals. The number of electrons in any particular shell or orbit can be found by the formula 2n² where n is the number of shell. In order to check whether the number of electrons are the same as the electronic configuration, we must see the atomic number because atomic number shows us the total number of electrons in any atom.

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ElenaW [278]

Explanation:

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Step 1: Wind moves the blades of the turbine.

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7 0

3 years ago

One of the radioactive isotopes used in medical treatment or analysis is chromium-51. The half-life of chromium-51 is 28 days. H

Goryan [66]

Answer : The time required for decay is, 84 days.

Explanation :

Half-life of chromium-51 = 28 days

First we have to calculate the rate constant, we use the formula :

$k=\frac{0.693}{t_{1/2}}$

$k=\frac{0.693}{28\text{ days}}$

$k=0.0248\text{ days}^{-1}$

Now we have to calculate the time required for decay.

Expression for rate law for first order kinetics is given by:

$t=\frac{2.303}{k}\log\frac{a}{a-x}$

where,

k = rate constant

t = time taken by sample = ?

a = let initial activity of the sample = 100

a - x = amount left after decay process = 12.5

Now put all the given values in above equation, we get

$t=\frac{2.303}{0.0248}\log\frac{100}{12.5}$

$t=83.9\text{ days}\approx 84\text{ days}$

Therefore, the time required for decay is, 84 days.

7 0

3 years ago

Why must power plants spend so much money and be so cautious in dealing with these materials?

shepuryov [24]

If you are referring to nuclear power plants and radioactive materials, then there is a high necessity to be cautious and stay safe because only by being safe you can prevent accidents like those caused in Ukraine and Japan. Unlike other types of power plants whose destruction in case of an accident can relatively easily be contained, nuclear power plants are extremely difficult to manage if things go out of hand since you can destroy the air around it, the water, the food by ruining the soil, and many other things.

8 0

3 years ago

How many double bonds does CCL2H2 have?

galben [10]

None. Both chlorines and both hydrogens are single-bonded to the central carbon atom; the molecule is comprised of four single bonds and no double bonds.

Hope this helps!

4 0

2 years ago

A 240.0 gram piece of copper is dropped into 400.0 grams of water at 24.0 °C. If the final temperature of water is 42.0 °C, what

ludmilkaskok [199]

The initial temperature of the copper piece if a 240.0 gram piece of copper is dropped into 400.0 grams of water at 24.0 °C is 345.5°C

<h3>How to calculate temperature?</h3>

The initial temperature of the copper metal can be calculated using the following formula on calorimetry:

Q = mc∆T

mc∆T (water) = - mc∆T (metal)

Where;

m = mass
c = specific heat capacity
∆T = change in temperature

According to this question, a 240.0 gram piece of copper is dropped into 400.0 grams of water at 24.0 °C. If the final temperature of water is 42.0 °C, the initial temperature of the copper is as follows:

400 × 4.18 × (42°C - 24°C) = 240 × 0.39 × (T - 24°C)

30,096 = 93.6T - 2246.4

93.6T = 32342.4

T = 345.5°C

Therefore, the initial temperature of the copper piece if a 240.0 gram piece of copper is dropped into 400.0 grams of water at 24.0 °C is 345.5°C.

Learn more about temperature at: brainly.com/question/15267055

8 0

2 years ago

Help plz I'm confused ​

Help plz I'm confused