Please i really need help it's due today

Answer:

C) 4.

Explanation:

Hello!

In this case, since the electron configuration of nickel at its ground-state, considering 28 as its atomic number and the number of electrons it has in one atom, is:

[tex]Ni^{28}:1s^2,2s^2,2p^6,3s^2,3p^6,4s^2,3d^8[/tex]

We can see it has four energy levels, 1, 2, 3 and 4, which are related to the following principal quantum number, that describes the energy of an electron in the atom and its most probable distance with respect to the nucleus.

Therefore, nickel has C) 4 different principal quantum numbers.

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Answer:

sopas

Explanation:

lagyan mo ng condense

There is a golden role of solubility, polar solute dissolve in polar solvent and non polar solute dissolve in non polar solvent. Therefore, the  total mass of the soup is 2,060gram.

Solutions are a homogeneous mixture of two or more substances. A solution is a homogeneous mixture of solvent and solute molecules. Solvent is a substance that is in large amount in solution. solute is the substance which is in small amount in a solution. There are two types of mixture that is homogeneous and heterogeneous. Solution is a homogeneous solution.

mass of soup= mass of water+ mass of vegetables + mass of meat

mass of water=1,500 grams

mass of vegetables= 350 grams

mass of meat=210 grams

substituting all the values in the above equation, we get

mass of soup= 1,500 grams+ 350 grams + 210 grams

                      = 2,060gram

Therefore, the  total mass of the soup is 2,060gram.

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Molarity after dilution : 0.0058 M

The number of moles before and after dilution is the same  

The dilution formula

 M₁V₁=M₂V₂

M₁ = Molarity of the solution before dilution  

V₁ = volume of the solution before dilution  

M₂ = Molarity of the solution after dilution  

V₂ = Molarity volume of the solution after dilution

M₁=0.1 M

V₁=6.11

V₂=105.12

[tex]\tt M_2=\dfrac{M_1.V_1}{V_2}=\dfrac{0.1\times 6.11}{105.12}=0.0058~M[/tex]

Answer:

yes

Explanation:

Answer:

yes

Explanation:

let's say you have ice, you put it on a pan then it heats up you get a liquid after a while it turns into a gas

Answer:

adding a catalyst will increase the reaction rate.

Explanation:

im like 95% sure thats right.

Answer:

A. C. D

Explanation:

ap ex

Answer:

[tex]E=9.62\times 10^{-21}\ J[/tex]

Explanation:

Given that,

The wavelength of a microwave is 7.42 mm or 0.00742 m

No. of photons, n = 359

We need to find the energy produced by this no of photons. It can be given by the formula as follows :

[tex]E=\dfrac{nhc}{\lambda}\\\\E=\dfrac{359\times 6.63\times 10^{-34}\times 3\times 10^8}{0.00742}\\\\=9.62\times 10^{-21}\ J[/tex]

or

[tex]E=9.62e^{-21}\ J[/tex]

So, the required energy is [tex]9.62\times 10^{-21}\ J[/tex].

Answer:

⬆️That guy deserves brainliest

Explanation:

Answer:c

Explanation:

The sentence that has an accurate punctuation is found in (Option B).

The punctuation marks are those marks that are use to make a piece of writing to have a complete meaning. A piece of writing will be meaningless if there are no attached punctuation marks.

The sentence that is correctly punctuated is;  "I bought all the ingredients for dinner: eggs, tomatoes, macaroni, and cheese—and told Molly to preheat the oven."(Option B)

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Answer:

group 18

Explanation:

The noble gases (Group 18) are located in the far right of the periodic table and were previously referred to as the "inert gases" due to the fact that their filled valence shells (octets) make them extremely nonreactive

Answer:group 18

Explanation

Answer:

D

Explanation:

A weather front is a transition zone between two different air masses at the Earth's surface. Each air mass has unique temperature and humidity characteristics. Often there is turbulence at a front, which is the borderline where two different air masses come together. The turbulence can cause clouds and storms.

Answer:

Glycogen: It is made up of a large chain of molecules. ...

Cellulose: The cell wall of the plants is made up of cellulose. ...

Starch: It is formed by the condensation of amylose and amylopectin. ...

Insulin: It is made up of a number of fructofuranose molecules linked together in chains.

Explanation:

Answer:

b

Explanation:

suspension is the heterogenos solution

Explanation:

What volume of silver metal will weigh exactly 2500.0 g. The density of silver is 10.5 g/cm3. cm3 = 2500.0 g / 10.5 g/cm3 = 238 cm3

What is the density of a piece of wood that has a mass of 25.0 grams and a volume of 29.4 cm3? d = .85 g/cm3

Answer:

K > Ca > Ge > Kr

Explanation:

The elements given are all in the 4th period on the periodic table.

       Kr, k, Ge, Ca;

Arranging their order from left to right;

         K, Ca, Ge, Kr

Atomic radius is taken as half the of the inter-nuclear distance (d) between two covalently bonded atoms of non-metallic elements or half the distance between two nuclei in the solid state of metals.

Across the periodic table atomic radii decreases progressively from left to right. This is due to progressive increase in the nuclear charge (number of protons in the nucleus) without an attendant increase in the number of electronic shells.

From the left to right; decreasing radii;

         K > Ca > Ge > Kr

Answer:

[tex]$Cu_2+(SO_3)^2 \rightleftharpoons CuSO_3 \ (insoluble)$[/tex]

[tex]$Cu_2+2(SO_3)^2 \rightleftharpoons [Cu(SO_3)_2]_2 \ (soluble)$[/tex]

Explanation:

A ligand may be defined as a molecule or an ion or that binds to the central metal atom in order to form a more coordination complex. Sulfite is one such ligand and it behaves similarly as hydroxide as a ligand.

Now, according to the question, when we react copper with sulfite ion, it forms copper sulfite. The equation is

[tex]$Cu_2+(SO_3)^2 \rightleftharpoons CuSO_3 \ (insoluble)$[/tex]

Now when excess of the sulfite ion is used in the reaction, we get a complex formation, which is shown by

[tex]$Cu_2+2(SO_3)^2 \rightleftharpoons [Cu(SO_3)_2]_2 \ (soluble)$[/tex]

The way the sulfite reacts is quite similar to hydroxide ion where they form a complex ion when hydroxide ion in excess is used in the reaction with metal cation.

Answer:

Metalloids and ions

Explanation:

Mercury is not solid at room temperature. (Metals)

Many nonmetals aren't good at conducting electricity. Oxygen for example. (Nonmetals)

Metalloids are always solid at room temp and are fair conductors. (Metalloids)

Ions are same as metalloids. (Ions)

PLS GIVE BRAINLIEST

Answer:

pH = 4.89

0.6171g of KOH must be added

Explanation:

Sodium acetate reacts with HCl producing acetic acid as follows:

NaC2H3O2 + HCl → HC2H3O2 + NaCl

That means the moles added of HCl are moles of acetic acid produced and moles of acetate are initial moles - moles of HCl

Moles HCl = Moles acetic acid:

0.204L * (0.452mol / L) = 0.0822 moles acetic acid.

Initial moles sodium acetate:

0.500L * (0.400mol / L) = 0.200 moles

Moles sodium acetate:

0.200 moles - 0.0822 moles = 0.1172 moles sodium acetate

The pH of this buffer (Mixture of a weak acid and its conjugate base) is obtained using H-H equation:

pH = pKa + log [A-] / [HA]

Where pH is pH of the buffer,

pKa is pKa of the buffer (4.74 for acetic acid)

[A-] Moles of sodium acetate -Conjugate base-

And HA moles of acetic acid -Weak acid-

pH = 4.74 + log [0.1172 moles] [0.0822 moles]

In 0.500L the moles of the buffer are:

0.500L * (0.200moles / 0.704L) = 0.142 moles of buffer

For a pH of 0.15 units more (4.89 + 0.15 = 5.04):

5.04 = 4.74 + log [Acetate] / [Acetic acid]

0.3 = log [Acetate] / [Acetic acid]

1.9953 = [Acetate] / [Acetic acid] (1)

And as:

0.142 = [Acetate] + [Acetic acid] (2)

Replacing (2) in (1):

1.9953 = 0.142 - [Acetic acid]  / [Acetic acid]

1.9953 [Acetic acid] = 0.142 - [Acetic acid]

2.9953 [Acetic acid] = 0.142 moles

[Acetic acid] = 0.0474 moles of acetic acid must remain after the addition of KOH.

In the beginning, moles of acetic acid are:

0.0822 moles * (0.500L / 0.704L) = 0.0584 moles.

That means moles added of KOH (Equal to moles of acetic acid that react) are:

0.0584 moles - 0.0474 moles = 0.0110 moles of KOH

In grams (Molar mass KOH = 56.1g/mol):

0.0110 moles KOH * (56.1g/mol) =

Answer:

When there is no spark from the reaction

Explanation:

The reaction between the acid and the magnesium metal goes into completion when there is no more spark from the magnesium. Also, the magnesium would have totally disappeared into solution.

These physical observation marks the end of the reaction.

When Mg reacts with HCl hydrogen bubbles are released. The completion of the given reaction can be determined by the presence of bubbles above the HCl.

[tex]\bold {Mg+ 2HCl\rightarrow MgCl_2 + H_2}[/tex]

In this reaction, Mg reacts with 2 moles of HCl to form 1 mole of Magnesium chloride and release hydrogen gas.

During reaction,

Therefore, the completion of the given reaction can be determined by the presence of bubbles above the HCl.

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Answer:

work out if it's either going to sink or float

Explanation:

this can be carried out by calculating the numbers

Answer:

53.5%

Explanation:

Step 1: Given data

Step 2: Calculate the mass corresponding to 0.00875 moles of KClO₃

The molar mass of KClO₃ is 122.55 g/mol.

0.00875 mol × 122.55 g/mol. = 1.07 g

Step 3: Calculate the percent by mass of KClO₃ in the mixture

We will use the following expression.

%m/m = mass of KClO₃/mass of the sample × 100%

%m/m = 1.07 g/2.00 g × 100%

%m/m = 53.5%

The percent by mass of KClO3 in the original mixture is 53.5%.

Since

The mass of the sample should be 2.00 g

Moles of KClO₃: 0.00875 mol

The molar mass of KClO₃ is 122.55 g/mol.

Now the mass is

= 0.00875 mol × 122.55 g/mol.

= 1.07 g

Now the percentage should be

= mass of KClO₃/mass of the sample × 100%

= 1.07 g/2.00 g × 100%

= 53.5%

hence, The percent by mass of KClO3 in the original mixture is 53.5%.

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Answer: #2 : s, solid & #3 : PbBr2

Explanation:

In the reaction [tex]\rm Li_2CO_3 (aq) + BaS (aq)\rightarrow LiOH (aq) + BaCo_3 (?)[/tex] the missing symbol is s . The PbBr₂ will produce a precipitate when mixed water. Hence option D is correct.

Chemical reaction is defined as a procedure that involves changing a substance's molecular or ionic structure, as opposed to changing its physical shape or undergoing a nuclear reaction. When atoms establish or break chemical bonds, chemical reaction take place. Reactants are the substances that begin a chemical reaction, while products are the compounds that are created as a result of the reaction.

Precipitation is defined as the mechanism by which water vapor in the atmosphere condenses and descends to the ground under the pull of gravity. Water vapor in the clouds condenses into increasing-sized droplets of water, forming precipitation. To replenish the water on the earth, precipitation is required. This world would be a vast desert if it didn't rain. Within an estuary, water level and water quality are impacted by the frequency and length of precipitation events.

Thus, in the reaction [tex]\rm Li_2CO_3 (aq) + BaS (aq)\rightarrow LiOH (aq) + BaCo_3 (?)[/tex] the missing symbol is s . The PbBr₂ will produce a precipitate when mixed water. Hence option D is correct.

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Thank you, also what are the options then I can help!

Answer:

The answer is

Explanation:

The number of molecules present can be found by using the formula

where n is the number of moles

N is the number of entities

L is the Avogadro's constant which is

6.02 × 10²³ entities

From the question we have

N = 4.21 × 6.02 × 10²³

We have the final answer as

Hope this helps you

Answer:

Speeds up when temperature is increased and can travel through a solid

Explanation:

Answer:

Bromine is a very reactive element. While it is less reactive than fluorine or chlorine, it is more reactive than iodine. It reacts with many metals, sometimes very vigorously. For instance, with potassium, it reacts explosively.

Explanation:

Answer: Bromine is a high reactive element. While it is not as reactive as fluorine or chlorine, it is still more reactive than iodine. It reacts with many metals, and even sometimes very aggressively. For example, when mixed with potassium, it will explode.  

Explanation:

Answer:

156.4g K

Explanation:

I'm not sure if it is correct but I think it should be this

What do we know so far?: 2K + 1Cl2 -> 2KCl, 2 mol of Cl2

What are we looking for?: #g of K

What is the ratio of K to Cl2?: 2:1

Set up equation: 2molCl2 x [tex]\frac{2mol K}{1 mol Cl2}[/tex]

Cancel unwanted units: 2 x [tex]\frac{2mol K}{1}[/tex]

Answer we got: 2 x 2mol K = 4mol K

Converting moles to grams: 4 x 39.1 (molar mass of K) = 156.4g K

Answer:

[tex]V = 0.117 \ L[/tex]

General Formulas and Concepts:

Chem

Explanation:

Step 1: Define

1.57 M KOH (potassium hydroxide)

10.3 g KOH

Step 2: Define conversions

Molar Mass of K - 39.10 g/mol

Molar Mass of O - 16.00 g/mol

Molar Mass of H - 1.01 g/mol

Molar Mass of KOH - 39.10 + 16.00 + 1.01 = 56.11 g/mol

Step 3: Convert

[tex]10.3 \ g \ KOH(\frac{1 \ mol \ KOH}{56.11 \ g \ KOH} )[/tex] = 0.183568 mol KOH

Step 4: Solve for Volume

Step 5: Check

We are given 3 sig figs. Follow sig fig rules.

[tex]0.116922 \ L \approx 0.117 \ L[/tex]

Answer:

The second answer

Explanation:

Phase changes is an example of physical change because it only changes the substance's appearance.

Answer: 1 and 4 are the answers

Explanation: because when you mix a sub since and it will have a chemical change

Answer:

0.0148 moles

Explanation:

Solid copper is oxidized with HNO₃:

Cu + 4HNO₃ → Cu²⁺ + 2 NO₃⁻ + 2H₂O + 2NO₂

Where 1 mole of Cu produce 1 mole of Cu²⁺ when nitric acid is in excess.

Moles of Cu that react (Molar mass Cu = 63.546g/mol):

0.94g * (1mol / 63.546g) = 0.0148 moles of Cu

And moles of Cu²⁺ produced are also: