What happens when there is a cluster of sunspots?

Answer:

Element

Explanation:

Other things on that list like alloy and compound can be broken down, but elements cannot

Answer:

If it is made from solid silver then it is an element. If it is made from a silver alloy then it is a mixture. If it is a silver plated plate (i.e. a plate made from say, copper but with a thin layer of silver on top) then it is an element on top of an element.

Explanation:

I'm assuming you're talking about solid silver, so, i believe an element.

Answer:

63.7g BaCl₂

Explanation:

Based on the chemical reaction:

2HCl + Ba(OH)₂ → BaCl₂ + 2H₂O

2 moles of HCl reacts per mole of barium hydroxide

To solve this question, we need to convert the moles of each reactant to moles and, using the chemical reaction, find limiting reactant as follows:

Moles Ba(OH)₂ - Molar mass: 171.34g/mol-

52.4g Ba(OH)₂ * (1mol / 171.34g) = 0.306 moles Ba(OH)₂

Moles HCl - Molar mass: 36.46g/mol-

25.6g HCl * (1mol / 36.46g) = 0.702 moles HCl

For a complete reaction of 0.702 moles HCl are required:

0.702 moles HCl * (1mol Ba(OH)₂ / 2mol HCl) = 0.351 moles of Ba(OH)₂

As there are just 0.306 moles, limiting reactant is Ba(OH)₂

That means the maximum amount of BaCl₂ produced is:

0.306 moles Ba(OH)₂ * (1mol BaCl₂ / 1 mol Ba(OH)₂) = 0.306 moles BaCl₂

In mass -Molar mass BaCl₂: 208.23g/mol-

0.306 moles BaCl₂ * (208.23g / mol) = 63.7g BaCl₂

Answer: [tex]K_2SO_4(aq)+2NaOH(aq)\rightarrow Na_2SO_4(aq)+2KOH(aq)[/tex]

Explanation:

A double displacement reaction is one in which exchange of ions take place. The salts which are soluble in water are designated by symbol (aq) and those which are insoluble in water and remain in solid form are represented by (s) after their chemical formulas.  

The balanced chemical equation is:

[tex]K_2SO_4(aq)+2NaOH(aq)\rightarrow Na_2SO_4(aq)+2KOH(aq)[/tex]

Answer:

Number of moles of water = 210 mol

Explanation:

Given data:

Mass of water = 3780 g

Number of moles of water = ?

Solution:

Formula:

Number of moles = mass/molar mass

Molar mass of water = 18 g/mol

Number of moles = 3780 g/ 18 g/mol

Number of moles of water = 210 mol

Answer:

1.510 × 10⁻¹³ g

Explanation:

Step 1: Given data

Number of atoms of vanadium: 1.000 × 10⁹ atoms

Step 2: Calculate the molecules of V₂O₅ that contain 1.000 × 10⁹ atoms of V

Each molecule of V₂O₅ has 2 atoms of V.

1.000 × 10⁹ atom V × (1 molecule V₂O₅/2 atom V) = 0.5000 × 10⁹ molecule V₂O₅

Step 3: Calculate the moles corresponding to 0.5000 × 10⁹ molecules of V₂O₅

We will use Avogadro's number: there are 6.022 × 10²³ molecules of V₂O₅ in 1 mole of V₂O₅.

0.5000 × 10⁹ molecule × (1 mol/6.022 × 10²³ molecule) = 8.303 × 10⁻¹⁶ mol

Step 4: Calculate the mass corresponding to 8.303 × 10⁻¹⁶ moles of V₂O₅

The molar mass of V₂O₅ is 181.88 g/mol.

8.303 × 10⁻¹⁶ mol × 181.88 g/mol = 1.510 × 10⁻¹³ g

Given

Lf=latent heat of fusion  of Al = 95 cal/g

Q = 1,265,730 cal

Required

mass of Aluminium

Solution

The heat to change the phase can be formulated :

Q = m.Lf (melting/freezing)

Input the value

1,265,730 cal = m . 95 cal/g

m = 1,265,730 cal : 95 cal/g

m = 13323.47 g

Explanation:

1. Latitude or distance from the equator – Temperatures drop the further an area is from the equator due to the curvature of the earth. In areas closer to the poles, sunlight has a larger area of atmosphere to pass through and the sun is at a lower angle in the sky.

Answer: increase the bicycles acceleration hope this helps :]

Explanation:

Answer:

Science is the pursuit and application of knowledge and understanding of the natural and social world following a systematic methodology based on evidence. Experiment and/or observation as benchmarks for testing hypotheses

Explanation:

The volume of concentrated HCl : 2.073 ml

Given

37% HCl by mass; density 1.19 g/mL

Required

The volume of concentrated HCl

Solution

Conversion to molarity :

37% x 1.19 g/ml =0.4403 g/ml

g/ml to mol/L :

=0.4403 g/ml x 1000 ml/L : 36.5 g/mol

=12.06 mol/L

or we can use formula :

[tex]\tt M=\dfrac{\%\times \rho\times 10}{MM}\\\\M=\dfrac{37\times 1.19\times 10}{36.5}\\\\M=12.06[/tex]

Dilution formula :

M₁V₁=M₂V₂

12.06 M x V₁ = 0.1 M x 0.25 L

V₁ = 0.0021 L = 2.073 ml

Answer: 184 g of nitrogen dioxide that are produced from 4 moles of nitric oxide

Explanation:

The balanced chemical reaction is:

[tex]2NO(g)+O_2(g)\rightarrow 2NO_2(g)[/tex]  

According to stoichiometry :

2 moles of [tex]NO[/tex] produce = 2 moles of [tex]NO_2[/tex]

Thus 4 moles of [tex]NO[/tex] will require=[tex]\frac{2}{2}\times 4=4moles[/tex]  of [tex]NO_2[/tex]

Mass of [tex]NO_2=moles\times {\text {Molar mass}}=4moles\times 46g/mol=184g[/tex]

Thus 184 g of nitrogen dioxide that are produced from 4 moles of nitric oxide

Answer:

[tex]K'=\frac{1}{16}[/tex]

Explanation:

Hello!

In this case, since the given reaction is:

[tex]A+ 2B \rightleftharpoons C+ \frac{5}{2} D[/tex]

Whereas the equilibrium constant is:

[tex]K=\frac{[C][D]^{5/2}}{[A][B]^2} =4.0[/tex]

However, the new target reaction reverses and doubles the initial reaction to obtain:

[tex]2C+5D \rightleftharpoons 2A+4B[/tex]

Whereas the equilibrium constant is:

[tex]K'=\frac{[A]^2[B]^4}{[C]^2[D]^5}[/tex]

Which suggest the following relationship between the equilibrium constants:

[tex]K'=\frac{1}{K^2}[/tex]

So we plug in to obtain:

[tex]K'=\frac{1}{4.0^2}\\\\K'=\frac{1}{16}[/tex]

Best regards!

Answer:

False

Explanation:

Using less electricity will result in less fuel being burnt which will result in less fuel needing to be extracted from the earth which will reduce society's impact on earth.

Find your answer in the explanation below.

Explanation:

PV = nRT is called the ideal gas equation and its a combination of 3 laws; Charles' law, Boyle's law and Avogadro's law.

According to Boyle's law, at constant temperature, the volume of a gas is inversely proportional to the pressure. i.e V = 1/P

From, Charles' law, we have that volume is directly proportional to the absolute temperature of the gas at constant pressure. i.e V = T

Avogadro's law finally states that equal volume of all gases at the same temperature and pressure contain the same number of molecules. i.e V = n

Combining the 3 Laws together i.e equating volume in all 3 laws, we have

V = nT/P,

V = constant nT/P

(constant = general gas constant = R)

V = RnT/P

by bringing P to the LHS, we have,

PV = nRT.

Q.E.D

Answer:

pH of 7 is neutral

pH of 4 is weak acid

Explanation:

hope it helps you..

Answer:

1. expanding

2. red, blue

3. red, spreading out

Explanation:

The percentage of C in CO = 42.9%

Given

CO compound

Required

Percentage of C

Solution

Proust :

Compounds are formed from elements with the same Mass Comparison so that compounds have a fixed composition of elements

Ar of C = 12 g/mol

MW of CO = 28 g/mol

%C :

[tex]\tt =\dfrac{Ar~C}{MW~CO}\times 100\%\\\\=\dfrac{12}{28}\times 100\%\\\\=42.9\%[/tex]

answer to this question is = 42.9 %

Explanation:

mark me as brainliest

Answer:

12.5%

Explanation:

From the question given above, the following data were obtained:

Half-life (t½) = 2 h

Time (t) = 6 h

Percentage remaining =.?

Next we shall determine the number of half-lives that has elapse. This can be obtained as follow:

Half-life (t½) = 2 h

Time (t) = 6 h

Number of half-lives (n) =?

n = t / t½

n = 6/2

n = 3

Finally, we shall determine the percentage of original dosage remaining as follow:

Amount remaining (N) = Original amount (N₀) /2ⁿ

N = N₀ / 2ⁿ

Divide both side by N₀

N/N₀ = 1/2ⁿ

Input the value of n i.e 3

N/N₀ = 1/2³

N/N₀ = 1/8

N/N₀ = 0.125

Multiply by 100 to express in percent.

N/N₀ = 0.125 × 100

N/N₀ = 12.5%

Thus, percentage of original dosage remaining is 12.5%

Answer:

D. Atoms are changed into new elements.

Explanation:

atoms rearrange to form one or more different substances.

Hope that helps!!!

Sorry if its worng :(

Answer:

It's actually C. Energy is given off or absorbed.

Explanation:

"All chemical reactions involve changes in energy. This may be a change in heat, electricity, light, or other forms of energy. Reactions that absorb energy are endothermic. Reactions that release energy are exothermic."

-LibreTexts Chemistry

Answer:

62.07 %

Explanation:

Chemical Formula =  (CH3)2CO = C3H6O

Mass of C = 12 g/mol

Mass of H = 1 g/mol

Mass of O = 12 g/mol

Mass of  C3H6O = 3(12) + 6(1) + 16 = 58 g/mol

Total mass of C in Acetone = 12 * 3 = 36 g

Mass Percent of C =  Total mass of C / Mass of Acetone   *  100

Mass percent = 36 / 58    *  100

Mass percent = 62.07 %

Answer:

N= mass/molar mass

complete the solve

Answer:

Your two answers are numbers of protons and electron and the second one is the atomic mass and weight.

Explanation:

God bless you are you got this

Answer:Number's 1, 2, and 4 are correct

Explanation:

Answer:

I think the answer is true

Answer:

increases

and the 2nd one increases

Answer:

21

Explanation:

To find the total atoms.

Multiply 3 *2 and you will get 6

Then multiply 3 * 5 and you will get 15.

You do this because there is 3 as a coefficient and is before the chemical compound. Furthermore, that means the same thing as a parenthesis.

Last of all, add 15 + 6 and you will get 21.

Therefore, there are a total of 21 atoms.

Answer:

B

Explanation:

Answer: The answer is D.gram

Explanation:

Answer: The lewis dot structure is attached below.

Explanation:

A Lewis dot structure is defined as the representation of atoms having electrons around the atom where electrons are represented as dots.

A ketene is an organic compound having general formula R′R″C=C=O, where R and R' are two different/same monovalent chemical groups.

The given chemical compound having formula [tex]C_2H_2O[/tex] is represented as [tex]H_2-C=C=O[/tex].

Total number of unshared electrons = 4 (left on oxygen atom only)

The lewis dot structure of [tex]C_2H_2O[/tex] is given in the image below.