if a +2 ion has 18 electrons, what element is it

Answer & Explanation:

Susana's red crystal sample is a compound because it was broken down into a gas and blue powder. It is not an element because elements cannot be broken down into simpler substances by ordinary means, such as heating.

Answer:

Susana's red crystal sample is a compound because it was broken down into a gas and blue powder. It is not an element because elements cannot be broken down into simpler substances by ordinary means, such as heating.

Explanation

Sample response form Edg

Considering the definiton of atomic number and atomic mass, the number of neutrons of the potassium is 21.

All atoms are composed of a central nucleus in which there are particles with a positive electric charge, the protons, and a neutral charge, the neutrons, around which other particles with a negative electric charge, which are electrons, move.

Atoms of different elements have different amounts of protons. The atomic number (which is identified by the letter Z) indicates the amount of protons that is present in the nucleus of an atom. This number is then responsible for defining the electronic configuration of the atom and the chemical properties of the element.

On the other side, the atomic mass (A) is defined as the sum of number of protons and number of neutrons:

Atomic mass = Number of protons  + Number of neutrons

In this case, the potassium (K) elements has atomic number 19. That means, the number of of protons is equal to 19. And the atomic mass is 40. So, the number of neutrons is calculated as:

40= 19  + Number of neutrons

Solving:

Number of neutrons= 40 - 19

Number of neutrons= 21

Hence, the number of neutrons of the potassium is 21.

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Answer:

i would say number 3 that was number 3

By changing  his opening to a more calm and positive approach pauld can become a an effective interpersonal communicator.Thus, option A is correct.

Interpersonal communication is the way of communicating messages with each other. From person to person the way or tone of interpersonal communication will change.

We have to keep a good and polite behaviour to everyone when communicating with them. If we are going to criticize more it will hurt some people more than we expect.

To approach in a positive manner, we have to avoid prejudices and predictions and more expectation about others. But keep them in a polite manner in a very genuine friendship.

Interpersonal communication is important in any field especially in business field where, people have to gather , plan and contribute with each other. Hence Paul have to open more calm and positive approach.

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Explanation:

Physical Change is a type of change where by no new chemical substance is formed. Physical changes are reversible. whilst Chemical change is a change where new chemical substance is always formed. Chemical changes are usually irreversible.

Examples of Physical Change include;

Melting of Ice

Melting of Candle

Grinding of chalk

Magnetization of Iron

Examples of Chemical Change includes;

Cooking of food

Rusting of Iron

Burning of Charcoal

Answer:

2 8 8 8 8 1

Explanation:

Answer: Step 1: List the known quantities and plan the problem. Known. 4.96 moles O2; 1 mol = 22.4

Explanation: I hope that helped.

Answer:

Explanation:

A. Decomposition

B. Synthesis

C. Combustion

D. neutralization

Answer: the density of the rock

55.91g/ml

Explanation:

The density of the rock after it had being placed in the cylinder of water so the calculation should look like this:

Volume of water substract the mass of the rock:

And that is 142.5 ml - 86.59g =

Answer 55.91 g/ml

So the density of the rock is 55.91g/ml

Answer:

force

Explanation:

because the force

Answer:

the line represents the condition where pressure and heat have the same effects.

Answer: C) The melting point of a substance at a specific pressure.

Answer:

There is this property called CATENATION which is basically the tendency of the atoms to bind to eachother. It is the MOST in the carbon after that silicon.

So the answer should Carbon atoms bond together to form groups of compounds.

here is what came up when i searched it up:

"The attraction between protons and electrons can also make clothes stick together in the dryer. When you dry clothes in the dryer, different fabrics rub together, and electrons from a cotton sock (for instance) may rub off onto a polyester shirt."

Sometimes, clothes can get stuck together after they come out of a dryer because of static electricity.

No, clothes may not start off as neutral. Whether clothes have static charges before going into the dryer depends on different things.

Static electricity happens when certain things touch and create an uneven amount of electrons. This can cause one material to have a positive charge and the other to have a negative charge. When clothes move and touch each other in a dryer, this rubbing can cause static electricity.

If the clothes are cleaned and dried correctly, they should have no charge or be evenly charged.

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Answer:

P(Kr) = 1.2 atm

Explanation:

According to Dalton law of partial pressure,

The total pressure inside container is equal to the sum of partial pressures of individual gases present in container.

Mathematical expression:

P(total) = P₁ + P₂ + P₃+ ............+Pₙ

Now we will solve this  problem by using this law

Total pressure = 1.60 atm

Partial pressure of neon = 0.40 atm

Partial pressure of krypton = ?

Solution:

P(total) = P(Ne)+ P(Kr)

1.60 atm = 0.40 atm +P(Kr)

P(Kr) = 1.60 atm -  0.40 atm

P(Kr) = 1.2 atm

The partial pressure of Krypton in the mixture has been 1.2 atm.

Partial pressure can be defined as the pressure exerted by a single gas in the solution.

According to Dalton’s law of partial pressure, the total pressure of the gas has been the summation of the partial pressure of each gas present in the mixture.

Total pressure = Partial pressure of A + Partial pressure of B + Partial pressure of C……

The given mixture has been consisted of neon and krypton. The total pressure of the mixture has been:

Total pressure = Partial pressure of Ne + Partial pressure of Kr

The total pressure = 1.60 atm.

The partial pressure of Ne = 0.40 atm.

Substituting the values:

1.60 atm = 0.40 atm + Partial pressure of Kr

Partial pressure of Kr = 1.60 - 0.40 atm

Partial pressure of Kr = 1.2 atm.

The partial pressure of Krypton in the mixture has been 1.2 atm.

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Answer:

Explanation:

What occurred then is as a result of nuclear fission. This occurs as the Uranium-235 split into two smaller nuclei while releasing high energy neutrons. These neutrons bombard existing U-235 in the atmosphere and this reaction continue in a spontaneous manner until a chain reaction is formed of U-235, whose fall out fills the environment. This process was what led to people been exposed to high intensity radiation in the days and months after the atomic bomb was dropped.

Answer:

Explanation:

Centigrade

Answer:

+3

12 electrons and 15 protons.

Explanation:

The element having 15 electrons and 15 protons have atomic number 15. We know that when an atom lose or gain the electron ions are formed.

Anion formation:

Anion is formed when electron is accept by an atom.

X + e⁻ → X⁻

Cation formation:

Cation is formed when electron lose be an atom.

X → X⁺ + e⁻

The given atom loses 3 electrons thus oxidation number will be +3 and cation is formed.

X → X³⁺ + 3e⁻

Now element X have 15 protons and 12 electrons.

Answer:

Each parent's half of the genes acquired  by the offspring. They  have two of each chromosome and hence two alleles of each gene, and one acquired from each parent.

Noble gas configuration for Li : [He]2s¹

In an atom, there are levels of energy in the shell and sub-shell

This energy level is expressed in the form of electron configurations.

Lithium with atomic number 3, then the electron configuration:

1s²2s¹

And for noble gas configuration or it can be called Condensed electron configurations :

[He]2s¹

Answer:

[He]2s¹

Explanation:

Answer:

0.010g of C-14 would be later after 50,000 years

Explanation:

The kinetics of radioactive decay follows the equation:

Ln (N / N₀) = -kt

Where N could be taken as mass after time t,

N₀ initial mass = 4.30g;

k is rate constant = ln 2 / t(1/2)

= ln 2 / 5730years = 1.2097x10⁻⁴ years ⁻¹

Replacing:

Ln (N / 4.30g) = -1.2097x10⁻⁴ years ⁻¹ * 50000 years

N / 4.30 = 2.36x10⁻³

N =

Answer:

1

Explanation:

Ag+

From the given reaction, it is clear that, Ag is gaining electrons from the base NH₃ . Hence, according to Lewis concept of acids and bases, Ag⁺ is the Lewis acid.

There are various concepts to define acids and bases. Among which the first was Arrhenius theory. This theory states that, acids are substances which can furnish H+ in solution and bases are substances giving OH- in solution.

Then Bronsted- Lowry concept states acids as proton donor and bases as proton acceptors. The most applicable theory for acids and bases is Lewis concept.

According to Lewis theory of acids and bases, acids are electrons acceptors and bases are electron donors.

The given reaction is written as:

[tex]\rm Ag^{+} + 2NH_{3} \rightarrow Ag(NH_{3})_{2}[/tex]

Here, Ag⁺ is the Lewis acid which accepts an electron from the Lewis base NH₃.

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Answer:

A

Explanation:

Answer:

It is A!

Explanation:

Answer is D formation of gas.

Explanation: I hope that helped/have a great day.

Answer: D

Explanation: trust

Answer:

Explanation:

D

Answer:

14.52%

Explanation:

The percentage by mass (WW%) is calculated by using the formula:

Mass of solute/mass of solution ×

100

The solute (Al) is 22.5g while the solvent (Al2O3) is 155g

Hence, percent by mass is:

22.5/155 × 100

= 0.1452 × 100

= 14.52%

A.conduction  i hope it helps

Answer:

conduction

Explanation:

Answer:

None of the above

Explanation:

Erikson's was a student of freud's and expanded of his theory of psychosexual development by emphasizing the importance of culture in parenting practices and motivations and adding three stages of adult development.