A student was using the periodic table to organize elements based on their ionization energy from lowest to highest. At the end of the class period, the student left one of the 4 spaces blank.

It looked like this: Ba, Co, ____, He.

Which of the following elements would best fit into this model?

A.
N would go into the blank because it fits the diagonal trend that points towards the upper right.

B.
Se would go into the blank because it fits the diagonal trend that points towards lower left.

C.
Kr would go into the blank because it is a noble gas and has a lower ionization energy than helium but higher than cobalt.

D.
Sb would go into the blank because it has more energy levels than cobalt which gives it a higher ionization energy than cobalt but less than helium.

Answer:

what is the question then we can help you out

Answer:

51.84

Explanation:

Answer:

A. 60 kPa

Explanation:

P2 = p1 times t2 / t1

i too used it

i thought it will help

nice time. .....

Explanation:

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Answer:

It is TRUE!

Explanation:

Answer:

True is your answer

Explanation:

Answer: Alcohol

Explanation:

Explanation:

number of moles can be derived from molarity law as shown in the figure

The number of moles of sodium hydroxide are in the solution should be considered as the 0.0875 moles.

Since there is 50.0 mL of a 0.350 M sodium hydroxide solution.

So here the no of moles should be

[tex]= Molarity * volume\\\\= 250 *10^-3 * 0.350[/tex]

= 0.0875 moles

hence, The number of moles of sodium hydroxide are in the solution should be considered as the 0.0875 moles.

Learn more about moles here: https://brainly.com/question/8759992

Answer:

The correct answer is C.

Explanation

The pH scale ranges from 0-14 so 7 is neutral.

Answer:

λ = 1.1×10⁸ m

Explanation:

Given data:

Frequency of wave = 2.7 Hz

Wavelength of wave = ?

Solution:

Formula:

Speed of wave = frequency × wavelength

Speed of wave = 3×10⁸ m/s

now we will put the values in formula.

3×10⁸ m/s = 2.7 s⁻¹ × λ

λ = 3×10⁸ m/s /2.7 s⁻¹

λ = 1.1×10⁸ m

Answer:

0.389 M

Explanation:

Using the formula; CaVa = CbVb

Where;

Ca = concentration of acid

Cb = concentration of base

Va = volume of acid

Vb = volume of base

Based on the provided information in the question, Va = 30mL, Ca=?, Vb = 27.83mL, Cb = 0.4190 M

Hence, CaVa = CbVb

Ca = CbVb/Va

Ca = 0.4190 × 27.83 ÷ 30

Ca = 11.6607 ÷ 30

Ca = 0.3886

Ca = 0.389 M

Therefore, the concentration of acetic acid in the vinegar is 0.389 M

Answer: A variable that is intentionally changed during an experiment

Explanation:Hope it works

Answer:

1. solid, 2.liquid, 3.gas.

Answer:

1 b. solid

2 a. liquid

3 c. gas

Answer:

B

Explanation:

Answer:

Potential

Explanation:

Answer:you killed a person

Explanation:that is a example

I looked around just put these into your own words :)

Explanation:

One common method of separation is filtration. Filters are used everywhere. We use them in our houses to filter dust and mites out of the air we breathe. We use them to filter impurities from our water.

It is important to be able to separate mixtures to obtain a desired component from the mixture and to be able to better understand how each component works.

In chemistry and chemical engineering, a separation process is commonly used to transform a mixture of substances into two or more distinct materials. The separated products might differ in chemical properties or some physical property, such as size or crystal modification or other separation into different components.

Hopefully this helps you out.

Answer:

Explanation:

The nucleophilic addition reaction of alcohol to a carbonyl compound in an acidic medium forms a hemiketal in the case of a ketone or a hemiacetal in the case of an aldehyde. When the carbonyl function is brought into contact with two alcohol functions, a ketal (for a ketone) or an acetal (for an aldehyde) is obtained.

From the image attached below, we will see how ketal formation occurs by the reaction of two molecules of ethanol with one cyclohexanone molecule.

Answer:

A

Explanation:

The product is the result of the chemical reaction hope that helped

Answer:

D. number of protons

Explanation:

Sana makatulong

Answer:

1.2 x 10²³atoms

Explanation:

Given parameters:

Mass of CO(NH₂)  = 12g

Unknown:

Number of Nitrogen atoms = ?

Solution:

Given compound;

     CO(NH₂);

  In;

         1 mole of CO(NH₂), we have 1 mole of N

let us find the number of moles of CO(NH₂);

  Number of moles  = [tex]\frac{mass}{molar mass}[/tex]

  Number of moles  = [tex]\frac{12}{60}[/tex]   = 0.2moles

Since

                  1 mole of CO(NH₂), we have 1 mole of N

                0.2 mole of CO(NH₂) will have 0.2mole of N

            1 mole of a substance contains 6.02 x 10²³ atoms

           0.2 mole of N will contain 0.2 x 6.02 x 10²³ atoms = 1.2 x 10²³atoms

Answer:

A.There are many active undersea volcanoes

B.There are long underwater mountain chains

Answer:

It is rich in organisms because sunlight passes through its shallow water enabling photosynthesis to occur.

Explanation:

I hope that helped!!

Answer: 8.89M

Explanation:

Answer:

90

Explanation:

Let ʸₓA be the resulting element when ²³⁴₉₂U under goes alpha decay.

Thus, the equation is given below

²³⁴₉₂U —> ʸₓA + ⁴₂He

The atomic number x of the resulting element can be obtained as follow:

92 = x + 2

Collect like terms

92 – 2 = x

90 = x

Therefore,

x = 90

Thus, the atomic number of resulting element is 90.

Answer:

Ka = [H₃O⁺] [SO₃²⁻] / [HSO₃⁻]

Kb = [OH⁻] [H₂SO₃] / [HSO₃⁻]

Explanation:

An amphoteric substance as HSO₃⁻ is a substance that act as either an acid or a base. When acid:

HSO₃⁻(aq) + H₂O(l) ⇄ H₃O⁺(aq) + SO₃²⁻(aq)

And Ka, the acid dissociation constant is:

When base:

HSO₃⁻(aq) + H₂O(l) ⇄ OH⁻(aq) + H₂SO₃(aq)

And kb, base dissociation constant is:

Answer:

F . chemical

Explanation:

Answer:

f

Explanation:

We are given:

Maximum concentration of Lead in water = 9 ppb

Mass of Lead in the given solution = 20 grams

Volume of water in the given solution = 250 mL

What is 1 ppb?

1 ppb, short for parts-per-billion. As from its name itself, ppb is used to find how many molecules of solute are present per 1 Billion molecules of the solvent

you can also use it in grams to get the formula:

1 ppb = 1 gram of solute / 1 Billion grams of Solvent

Finding the Ideal ppb concentration:

We are given that the maximum allowed concentration is 9 ppb

which means that we need 9 grams of the solute per 1 Billion grams of Solvent:  9 grams of Solute / 10⁹ grams of Solvent

ppb Concentration of the given solution:

We have 20 grams of Solute in 250 mL of water

Since the density of water is 1 gram/mL

20 grams of Solute / 250 grams of Solvent

As we can see, this fraction is FAR more large that the maximum ppb concentration

This means that the concentration of Lead in the Given solution is higher than the maximum amount and Hence, is unfit to drink

Answer:

at the negative cathode

Explanation:

Reduction happens at the negative cathode because this is where positive ions gain electrons. Oxidation happens at the positive anode because this is where negative ions lose electrons.

Answer:

B. in the cathode of an electrolytic cell

Explanation:

Given :

Mass of neon gas at STP.

To Find :

The volume of 139.05 g of neon gas at STP.

Solution :

Molar mass of neon, M = 20 g.

Number of moles in 139.05 g of neon :

n = 139.05/20 ≈ 7 moles

We know, volume of 1 mole of any atom/molecules in STP is 22.4 L of volume.

So, volume of 7 moles of neon is :

V = 7×22.4 L

V = 156.8 L

Therefore, volume of 139.05 g of neon gas at STP is 156.8 L.

Here ya go, hope this helps! :)