first 30 elements with their atomic mass​

Answer:

D

Explanation:

In the periodic table the noble gases are place in same column because the valence electron configuration is similar in all noble gas elements. Thus option D is correct.

A periodic table is defined as an organization of all known elements in increasing atomic number and repeating chemical properties.

It can also be defined as a tabular arrangement of chemical elements ordered by increasing atomic number and element groups.

There are more than 118 elements are arranged in modern periodic table.

Noble gases are defined as any of a class of rare gases that includes helium, neon, argon, krypton, xenon, and, most commonly, radon and display high stability and extremely low reaction rates.

Electronic configuration are defined as the electron configuration around the nucleus of a specific atom or molecule.

Thus, in the periodic table the noble gases are place in same column because the valence electron configuration is similar in all noble gas elements. Thus option D is correct.

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Answer:

Boiling the subtance

Explanation:

To determine the nature of an unknown liquid the first thing you can do is boil it:

* If the sample is water, the boiling point must be near to 100°C

*When all pure water is evaporated, there is no residue, the glass must be empty.

* But if the sample is salt water, when all water is evaporated, you will see a solid white residue that, possibly, is salt.

Answer:

they are called isotopes

Answer:

c

Explanation:

because potential energy is created with the position of a body when you pick up something the thing will have stored energy which is transferred from you so the stored energy is potential energy created by the position of a body that when you see over your head you scared of that thing not to bit you because it has stored energy if you see the thing already failed on the ground you wouldn't scared of that because the enery is already gone

Hope help you

because without the extra wheels the vehicle would be to heavy and not be able to support the extra weight thus the vehicle would be useless hope this helped brainlies plz

Answer:

A. The temperature is always lower.

Explanation:

Just took the test on Edg. 2020

Give me branliest please

i think it is this

Explanation:

Answer:

200 meters.

Explanation:

2000 centimeters is 20 meters

100 centimeters = 1 meter

2000 divided by 100 = 20

Explanation:

Thank you ☺️☺️

Answer:

152 more miles you will have to drive the third day to reach the destination.

Explanation:

First you must know the distance during the first two days. If you drive 692 miles on the first day and 674 miles on the second day, to get the distance traveled on both days you must add both amounts traveled:

692 miles + 674 miles= 1,366 miles

Knowing that there are 1,518 miles from West Lafayette to Provo, UT, to know the number of miles you will have to drive on the third day to reach your destination, you must subtract between the total distance and the distance traveled in the first two days. This is:

1,518 miles - 1,366 miles= 152 miles

152 more miles you will have to drive the third day to reach the destination.

Answer:

by damaging or changing a cell's DNA

Explanation:

Answer: 5.248

Explanation: 0.53/0.1010 = 5.24752475248, and round to the thousandths.

Answer: 22: C

              23: A

              24: A

              25: D

              26: B              

Explanation: I hope that this helped :)

Answer:

22) b. stainless steel.

23) c. they are all substances.

24) b. a compound can only be separated into its components by chemical means.

25) a. substances are compounds, mixtures are not.

26) b. capitalized

extra: not 100 percent sure of 25

Answer:

uhm-

Explanation:

chile, anyways so-

Answer:

If atoms gain electrons, they become negative ions, or anions. ... A fluorine atom has nine protons and nine electrons, so it is electrically neutral. If a fluorine atom gains an electron, it becomes a fluoride ion with an electric charge of -

Explanation:

Answer:

Add and electron and a proton

Explanation:

You would have to add a proton and an electron to F to get it to be Ne

Answer:279.1 K

Explanation:

You'll be using Gay-Lussac's Law for this. P1/T1=P2/T2

I have a class for this, and one of the practice questions was formatted this way, so I used that format and substituted said numbers as needed

P1:67 Pa

P2:60 Pa

T1:250 K

T2:?

I really hope this helps!

Answer:

Carbon dioxide - CO.

Benzene - C6H.

Carbon tetrachloride - CCl.

Methane - CH.

Ethylene - C2H.

Explanation: Some examples of atoms with nonpolar convalent bonds. Hope this was found useful!!

Non polar covalent compounds have no net dipole moment due to charge separation. Some examples are, CO₂, H₂, N₂,O₂ etc.

Covalent bonds are formed by the sharing electrons between atoms. Covalent bond is comparatively weaker than ionic bonds. Atoms of deficient number of electrons will combine by sharing their valence electrons and forms covalent bonds.

When one atom has more electronegativity, then the shared pair of electrons will  attracted into the electronegative atom. This creates a charge separation and a dipole moment.

However, if the electronegative atoms are linear in geometry from the central less electronegative atom then the dipole moment cancel each other and the compound become non polar as in the case of CO₂.

All gases in molecular states are covalently bonded and are non polar such as H₂, N₂,O₂ etc.

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Answer:

It's called moon phase

Explanation:

hope this helps

Answer:

see below

Explanation:

Sulfur and phosphorous can violate the octet rule and have an expanded octet, so molecules of these elements can contain more than eight valence electrons. In contrast, nonmetal elements in period 2 can't have an expanded octet because they don't have d orbitals. These elements must obey the octet rule and can hold only up to eight valence electrons. Period 2 elements can fill their outer orbitals by covalently bonding with one other atom of the same element.

Answer:

You will change which food dye is used. You will measure how quickly the dyes diffuse. You could use a timer to see how long the dye takes to completely diffuse.

The information regarding the change in the variable should be described  below:

The following information should be considered:

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Answer:1-Diffusion

2-Cerebral edema

Explanation:

The process of water migrating from areas of low electrolyte concentration to areas of high electrolyte concentration is called diffusion.

Cerebral edema is the medical term for the swelling of the brain.

Diffusion is a process where the substance or ions of from a low concentration to a high concentration. It occurs against the concentration gradient, so it needs energy.

Cerebral edema is a condition where fluid gets filled in the brain and the brain swells and make pressure on the skull called intracranial pressure.

Thus, Diffusion is the mechanism by which water moves from regions with low electrolyte concentrations to regions with high electrolyte concentrations.

The medical term for brain swelling is cerebral edema.

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Answer:

An atom's electronegativity is affected by both its atomic number and the distance at which its valence electrons reside from the charged nucleus. The higher the associated electronegativity, the more an atom or a substituent group attracts electrons.

Explanation:

Hope this helps :)

Answer:

The absorbance of the solution is 0.21168.

Explanation:

Given that,

Wavelength = 500 nm

Molar absorptivity = 252 M⁻¹ cm⁻¹

Number of moles = 0.00140

Volume of solution = 500.0 mL

Length = 3.00 mm

We need to calculate the molar concentration

Using formula of the molar concentration

[tex]C=\dfrac{N}{V}[/tex]

Where, N = number of moles

V = volume

Put the value into the formula

[tex]C=\dfrac{0.00140}{0.5000}[/tex]

[tex]C=0.0028\ M[/tex]

We need to calculate the absorbance of the solution

Using formula of absorbance

[tex]A=\epsilon C l[/tex]

Put the value into the formula

[tex]A=252\times0.0028\times0.300[/tex]

[tex]A=0.21168[/tex]

Hence, The absorbance of the solution is 0.21168.

The absorbance of a compound, with a molar absorptivity at 500 nm wavelength of 252 M⁻¹ cm⁻¹, prepared by dissolving 0.00140 moles of a solute in enough water to make a 500.0 mL solution, measured in a 3 .00 mm pathlength cell, is 0.212.

First, we will calculate the molarity of the compound, which is equal to the moles of solute divided by the liters of solution.

[tex]M = \frac{0.00140mol}{0.5000L} = 0.00280 M[/tex]

Then, we will convert 3.00 mm to cm using the conversion factor 1 cm = 10 mm.

[tex]3.00 mm \times \frac{1cm}{10mm} = 0.300 cm[/tex]

Finally, we will calculate the absorbance of the compound using the Beer–Lambert equation.

[tex]A = \epsilon \times b \times C[/tex]

where,

[tex]A = \epsilon \times b \times C = \frac{252}{M.cm} \times 0.300 cm \times 0.00280 M = 0.212[/tex]

The absorbance of a compound, with a molar absorptivity at 500 nm wavelength of 252 M⁻¹ cm⁻¹, prepared by dissolving 0.00140 moles of a solute in enough water to make a 500.0 mL solution, measured in a 3 .00 mm pathlength cell, is 0.212.

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Answer:

There's a lot of answers.

Explanation:

Last year, I presented a paper on population growth in the United States between the years 1975 and 2015. The data involved numbers and figures. This data was difficult to present in textual format, so I turned to graphing. The graph helped me break down and simplify complex numerical data so my audience could more easily understand it.

A time when I found it easier to communicate with a graph than with text was when I wanted to make a presentation about the importance of education.

Communication simply means sending a message from one person to another person. Graphs can be used when one wants to make a visual representation of data.

I used graphs when I wanted to make a presentation about the importance of education. I wanted to show the audience how certain regions like the European countries are well developed than African countries. The graph was vital in visualizing this.

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