All categories

3 years ago

Which element contains four electrons in its third and outer main energy level?

Chemistry

1 answer:

UkoKoshka [18]3 years ago

6 0

Answer:

valence electrons

Explanation:

The valence electrons are the outer most electrons and the principal energy level in which they belong will vary for .

You might be interested in

Is Pb(NO3)2 soluble or insoluble?

Sedaia [141]

Answer: it is soluble

Explanation: nitrates are soluble.

4 0

4 years ago

Select all that apply. Which equations are correct?

antoniya [11.8K]

Answer: Dang I wish I wasn't on a school chrome, that way I can see the photo without it getting blocked *cries*

Explanation:

3 0

3 years ago

Read 2 more answers

Dna is approximately 2.5 nm in length. of an average man is 5 ft 10 in. tall, how many dna molecules could be stacked to extend

Angelina_Jolie [31]

To determine the number of dna molecules that can be stacked as requested in this item, we convert the given measurements in a single unit. For simplicity, we convert all the lengths to meters.

Length of DNA molecule = (2.5 nm)(1 x 10^-9 m/1 nm) = 2.5 x 10^-9 nm

Height of a person = (5 ft 10 in)(12 inches/ 1ft)(2.54 cm/1 in)(1 x 10^-2 m/ 1 cm)
= 1.778 m

Then, divide the height of the person by the length of a single DNA molecule.

n = 1.778 m / (2.5 x 10^-9)
n = 7.112 x 10^8

Hence, the number of DNA would be 7.112 x 10^9.

5 0

4 years ago

Read 2 more answers

The source of Rain clouds snow is ozone True Or False

lilavasa [31]

It is false

Precipitation - What makes clouds, rain, snow, hail and sleet. When warm, wet air rises, it cools, and water vapor condenses out to form clouds. A cloud is made up of small drops of water or ice crystals, depending on its height and how cold is the surrounding air.

5 0

3 years ago

The Environmental Protection Agency has determined that safe drinking

dmitriy555 [2]

Answer:

b) $\bar X \pm t_{\alpha/2}\frac{s}{\sqrt{n}}$

The confidence interval for this case is given (6.21, 6.59)

So we can conclude at 95% of confidence that the true mean for the PH concentration is between 6.21 and 6.59 moles per liter

c) Since the confidence interval not contains the value 7 we reject the hypothesis that the true mean is equal to 7. And the same result was obtained with the t test for the true mean.

Explanation:

We assume that part a is test the claim. And we can conduct the following hypothesis test:

Null hypothesis: $\mu =7$

Alternative hypothesis $\mu \neq 7$

The statistic is to check this hypothesi is given by:

$t = \frac{\bar X -\mu}{\frac{s}{\sqrt{n}}}$

We know the following info from the problem:

$\bar X = 6.4 , s=0.5, n =30$

Replacing we got:

$t = \frac{6.4-7}{\frac{0.5}{\sqrt{30}}}= -6.573$

And the p value would be:

$p_v= 2*P(Z$

Since the p value is very low compared to the significance assumed of 0.05 we have enough evidence to reject the null hypothesis that the true mean is equal to 7 moles/liter

Part b

The confidence interval is given by:

$\bar X \pm t_{\alpha/2}\frac{s}{\sqrt{n}}$

The confidence interval for this case is given (6.21, 6.59)

So we can conclude at 95% of confidence that the true mean for the PH concentration is between 6.21 and 6.59 moles per liter

Part c

Since the confidence interval not contains the value 7 we reject the hypothesis that the true mean is equal to 7. And the same result was obtained with the t test for the true mean.

6 0

3 years ago

Which element contains four electrons in its third and outer main energy level? ​

Which element contains four electrons in its third and outer main energy level?