I am timed please help!!

Answer:

mg

Explanation:

Answer:

57.54% is the percentage of gold by mass in the alloy.

Explanation:

The mass of the mixture is 9.35g. That is:

9.35g = Mass Gold + Mass Silver

Mass silver = 9.35g - Mass gold (1)

Now, the volume of the jewelry is the sum of volumes of gold and silver:

0.654cm³ = Mass Gold / 19.5g/cm³ + Mass silver / 10.5g/cm³ (2)

Volume = Mass / Density.

Replacing (1) in (2):

0.654cm³ = Mass Gold / 19.5g/cm³ + (9.35g - Mass gold) / 10.5g/cm³

0.654 = 0.051282 Mass Gold + 0.890476 - 0.095238 Mass gold

-0.236476 = -0.043956 Mass gold

Mass gold = 5.38g

And mass percent of gold in the alloy is:

5.38g / 9.35g * 100 =

Answer

The first health care worker said, "Anatomy and Physiology makes the difference between me being a nurse and a great nurse?

Explanation:

I got the correct answer

Lead 214 emits then beta electrons to transform into bismuth 214 and polonium 214, which produces lead 210 through the emission of a third alpha particle. This series of transformations take place in a time span roughly equal to an hour.

Hope this helps, if I am right, brainliest? :))))

Answer:

The correct answer is "inferior".

Explanation:

In anatomy, the term inferior is used to describe parts of the body that are below other part used as reference. Inferior comes from the Latin "inferus" that means "below". In this case, the mouth will always be inferior to the nose, it doesn't matter if the boy was standing on his head or if he is in other position.

Answer:

correct answer, inferior.

Explanation:

of little or less importance, value, or merit always felt inferior to his older brother. 2a : of low or lower degree or rank. b : of poor quality : mediocre. 3 : situated lower down : lower.

If one person is regarded as inferior to another, they are regarded as less important because they have less status or ability. He preferred the company of those who were intellectually inferior to himself.

Hope this helped!

Answer:

[tex]m_{water}=50.25g[/tex]

Explanation:

Hello,

In this case, considering that the by-mass percent of water is:

[tex]\% m/m=\frac{m_{water}}{m_{sample}}*100\%[/tex]

Given such percent and the mass of the sample, we can find the mass of water in grams in the sample by solving for it as shown below:

[tex]m_{water}=\frac{\%m/m*m_{sample}}{100\%}\\ \\m_{water}=\frac{25\%*201g}{100\%}\\ \\m_{water}=50.25g[/tex]

Best regards.

Answer:

bonded

Explanation:

Compounds are two elements bonded together.

A mixture is multiple substances blended together.  The substances aren't bonded together and can easily be extracted  from each other.

Answer:

False, False, True, True, False, True

Explanation:

true? no false.   ...   no its true uhhhhh no gotta be false true. false. true. fase. gotta be tru false or maybe its true? nah its false

pls brainliest?

Answer:

The answer is 1.61 × 10²³ atoms

Explanation:

To determine number of atoms, we will use the formula below

Number of atoms = number of moles (n) × avogadro's constant (6.02 x 10²³)

n was not provided, hence we will solve for n

n = mass/ molar mass

molar mass of carbon monoxide, CO (where C is 12 and O is 16) is 12 + 16 = 28

mass was provided in the question as 7.48

n = 7.48/28

n = 0.267

Hence,

number of atoms = 0.267 × 6.02 x 10²³

= 1.61 × 10²³ atoms

Answer:

The total amount of Au is $ [tex]2.0\times10^{24}[/tex]

Explanation:

Given that,

Mass of 1.0 ml of Au [tex]m=4\times10^{-2}\ g[/tex]

Total volume of water in oceans [tex]V=1.5\times10^{21}\ L[/tex]

We need to calculate the volume in ml

Using given volume

[tex]V=1.5\times10^{21}\times1000\ mL[/tex]

[tex]V=1.5\times10^{24}\ mL[/tex]

We need to calculate the total mass of Au  

Using given data

[tex]1\ ml\ volume = 4\times10^{-2}\ g[/tex]

[tex]1.5\times10^{24}\ ml=4\times10^{-2}\times1.5\times10^{24}[/tex]

So, The total mass of Au is [tex]6\times10^{22}\ g[/tex]

The mass will be in ounce,

[tex]Mass=0.035274\times6\times10^{22}[/tex]

[tex]Mass=2.12\times10^{21}\ ounce[/tex]

The total amount of the Au Will be

[tex]Total\ amount=2.12\times10^{21}\times948[/tex]

[tex]Total\ amount=2.0\times10^{24}[/tex]

Hence, The total amount of Au is $ [tex]2.0\times10^{24}[/tex]

Answer:

the protection one

Explanation:

the cell wall acts a barrier

Answer:

if were talking about berylium then the answer should be 2 because it wants to move 2 spaces back (losing electrons) to become a nobel gas so the answer is 2+

Explanation:

it has 2 valence electrons YW :)    

A nucleus with 4 protons has a positive charge of +2.

Protons may be defined as the type of sub-atomic particles that are present in the nucleus of an atom along with the neutrons. These sub-atomic particles possess a positive charge in nature. It may be thought that protons are discovered by Ernest Rutherford.

Beryllium has a nucleus with 4 protons, which means that it has an atomic number of 4. This element belongs to the alkaline earth metals in group 2. Beryllium has the capability to lose two electrons in order to attain a noble gas configuration and occupy stability. It has an electronic configuration [tex]1s^2, 2s^2[/tex]. So, in order to make it octet fulfilled, it loses two electrons and becomes positively charged.

Therefore, a nucleus with 4 protons has a positive charge of +2.

To learn more about Protons, refer to the link:

https://brainly.com/question/1805828

#SPJ2

Answer:

c

Explanation:

From the equation, we can say that we need thrice the number of hydrogen than that of nitrogen

we are given 3 moles of nitrogen and 11 moles of hydrogen

but thrice the number of moles of nitrogen is 9, hence we have hydrogen in excess or Hydrogen is the excess reagent

Since we had 11 moles of Hydrogen and we only needed 9, 2 moles of hydrogen are left over

From the equation, we can see that the moles of ammonia formed will be twice the moles of nitrogen

Since 3 moles of nitrogen are used, the reaction will give us 6 moles of Ammonia and NOT 12 moles, therefore c is the correct answer

Since we have hydrogen in excess, our reaction is being limited because we have less Nitrogen, Hence Nitrogen is the Limiting Reagent

Option C is the only false statement

The false statement is that "12.0 moles of ammonia are produced"

According to the equation of reaction:

N₂  +  3H₂  >>>>>  2NH₃

1  mole of N₂ reacts with 3 moles of H₂

3 moles of N₂ will react with 9 moles of H₂

Since 3 moles of N₂ is said to react with 11 moles of H₂ (instead of 9 moles of H₂), H₂ is in excess by 2 moles. That is, N₂ is the limiting reactant.

Since N₂ is the limiting reactant:

1 mole of  N₂ produces 2 moles of NH₃

3 moles of N₂ will produce 6 moles of NH₃

Therefore, we can conclude that:

Learn more here: https://brainly.com/question/19555927

Answer:

Titration is used to determine the concentration of unknown solutions.

A dipole moments is a measurement of the separation of two opposite electrical charges

We have that The isotope of copper with the atomic mass of the isotope copper 62.930 amu is Cu 63

From the question we are told

the atomic mass of the isotope copper-__ is 62.930 amu

Generally

Copper is the 29th element of the the periodic table with an atomic mass of 29.

Copper as an elementt has 2 stable isotopes which are

Cu 63

Cu 65

Therefore

The isotope of copper with the atomic mass of the isotope copper 62.930 amu is Cu 63

For more information on this visit

https://brainly.com/question/17756498

Answer:

Division by zero is undefined because there is no other number to divide it by.

Explanation:

Unlike 2/2, 2/0 doesn't have anything to divide the 2 by which makes it undefined and impossible to solve.

The division by zero is undefined​, because whatever response we may give, we will then have to concur that the answer times 0 = 1, which is illogical because anything multiplied by zero is zero.

Since any attempt at definition results in a contradiction, the outcome of a division by zero cannot be defined. a=r*b. r*0=a. (1) (1) But because r*0=0 for all r, there is no solution to the equation unless a=0 (1).

Again, mathematicians have left zero divided by zero as an open problem because they are both equally valid and, to be honest, neither of them is consistent with the rest of mathematics.

Mathematically, it is impossible to divide a number by zero, just as in this illustration. Or, at the very least, there isn't currently a means to do that. Numerous attempts have been made to figure out how to divide by zero, as mathematicians are constantly looking for solutions to intriguing mathematical issues.

Thus, The division by zero is undefined​, because whatever response we may give, we will then have to concur that the answer times 0 = 1.

To learn more about division by zero is undefined, follow the link;

https://brainly.com/question/11523699

#SPJ2

Answer:

a. The balanced chemical equation is written below and this is a type of double displacement reaction.

Explanation:

When barium chloride reacts with copper sulfate, a white precipitate of barium sulfate is observed.

The chemical equation for the reaction of barium chloride and copper sulfate follows:

b.

2FeSO4--(heat)---> Fe2O3 + SO2+ SO3

This Reaction is an example of Thermal Decomposition Reaction.

Answer:

helium i think

Explanation:

Answer:

n = 1.3 x 10¹⁸ photons

Explanation:

First we need to calculate the amount of energy released in given time:

E = Pt

where,

E = Energy  = ?

P = Power = 4 mW = 0.004 W

t = time = 115 s

Therefore,

E = (0.004 W)(115 s)

E = 0.46 J

Now, this energy can be given in forms of photons as:

E = nhc/λ

where,

n = No. of photons = ?

h = Plank's Constant = 6.626 x 10⁻³⁴ J.s

c = speed of light = 3 x 10⁸ m/s

λ = wavelength of light = 5650 x 10⁻¹⁰ m

Therefore,

0.46 J = n(6.626 x 10⁻³⁴ J.s)(3 x 10⁸ m/s)/(5650 x 10⁻¹⁰ m)

n = (0.46 J)/(3.5 x 10⁻¹⁹ J)

n = 1.3 x 10¹⁸ photons

Answer:

1.308 x 10¹⁸ photons were emitted from the laser pointer.

Explanation:

Given;

wavelength of the photon, λ = 5650  Å = 5650 x 10⁻¹⁰ m

power emitted by the source, P = 4 mW = 4 x 10⁻³ W

time of photon emission, t = 115 s

The energy of a single photon is given by;

E = hf

f = c / λ

[tex]E = \frac{h c }{\lambda}[/tex]

where;

c is speed of light = 3 x 10⁸ m/s

h is Planck's constant = 6.626 x 10⁻³⁴ Js

[tex]E = \frac{(6.626 *10^{-34}) (3*10^8) }{5650*10^{-10}}\\\\ E = 3.518*10^{-19} \ J[/tex]

Energy of the source (laser pointer) = P x t

                                                           = (4 x 10⁻³ W) (115 s )

                                                           = 0.46 J

If no energy is lost, then emitted energy by the source must be equal to total energy of then photons;

[tex]E_T = n E_{photon}\\\\n = \frac{E_T}{E_{photon}}\\\\n = \frac{0.46}{3.518*10^{-19}}\\\\n = 1.308*10^{18} \ photons[/tex]

Therefore, 1.308 x 10¹⁸ photons were emitted from the laser pointer.

Answer:

Pressure will stay the same if volume stays the same.

Answer:

Volume is inversely proportional to pressure, meaning if one goes up the other goes down and vise-versa. With volume remaining the same and there are no other given factors, pressure also remains the same

Answer:

1. Diagram C.

2. Diagram A.

Explanation:

1. Calcium atom, Ca has 20 protons and 20 electrons. On the other hand, Calcium ion, Ca^2+ has 20 protons and 18 electrons. This is true because the +2 charge on the calcium ion, Ca^2+ indicates that the calcium atom, Ca has loss 2 electrons.

From the above illustration we can say that calcium ion, Ca^2+ has the following:

Proton = 20

Electron = 18

Therefore, diagram C indicates calcium ion, Ca^2+.

2. Fluorine atom, F has 9 protons and 9 electrons. Fluoride ion, F¯ has 9 protons and 10 electrons. This is so because the –1 charge on the fluoride ion, F¯ indicates that the fluorine atom, F has gained 1 electron.

Thus, we can say that the fluoride ion, F¯ has the following:

Proton = 9

Electron = 10

Therefore, diagram A represent fluoride ion, F¯.

Answer:

its a tree becoz charcoal came from wood

Answer:

Ionic bonds ussally form with a metal, and a non metel elements, so the answer would most likley be B.

Explanation:

hope I could help

Answer:

[tex]\boxed {\tt 2.71169355 \ mL}[/tex]

Explanation:

Density can be found using the following formula:

[tex]d=\frac {m}{v}[/tex]

Rearrange the formula for v. Multiply both sides by v, then divide both sides by d.

[tex]d*v =\frac {m}{v}*v[/tex]

[tex]d*v=m[/tex]

[tex]\frac{d*v}{d}=\frac{m}{d}[/tex]

[tex]v=\frac{m}{d}[/tex]

The volume can be found by dividing the mass by the density. The mass is 2.69 grams and the density is 0.992 grams per milliliter.

[tex]m= 2.69 \ g\\d= 0.992 \ g/mL[/tex]

Substitute the values into the formula.

[tex]v=\frac{2.69 \ g}{0.992 \ g/mL}[/tex]

Divide. Note that the grams, or g, will cancel each other out.

[tex]v=\frac{2.69}{0.992 \ mL}[/tex]

[tex]v= 2.71169355 \ mL[/tex]

The volume of the water is 2.71169355 milliliters.

Answer:

compound

Explanation:

MgO is an inorganic compund :) The simplest explanation is that it's not an element b/c there's two elements (Mg & O) in the substance, and it's not a mixture b/c you can't easily separate the two elements.

Answer:

magnesium when magnesium is burnt by heat it forms an compound called magnesium oxide

Answer:

C.The particles in the hot water will slow down, while the particles in the cold water will speed up

Explanation:

Heat causes changes in the molecules of substances when applied to them. The molecules of water, as a case study used in this question, when heated has an increased kinetic energy which causes its particles to move faster i.e. speed up. Also, when water is freezed or cold, it's particles move slower i.e. slow down due to decreased kinetic energy.

Hence, when a hot glass of water and a cold glass of water are placed on a kitchen table for 1 hour, they don't remain in their respective thermal state.

- The hot water (with an increased movement of molecules) begin to cool down, hence, its particles slows down as it gets cold or less hot.

- Likewise, the cold water (with a decreased movement of molecules) begins to get warmer, hence, it particles speedens up as it gets warmer.

Therefore, The particles in the hot water will slow down, while the particles in the cold water will speed up

The image of the bonds are missing, so i have attached it.

Answer:

A) - Sigma bond

-Sp³ and Sp³

- None

B) - Sigma and pi bond

- Sp² of C and p of O

- p of C and P of O

Explanation:

A) For compound 1;

- the molecular orbital type is sigma bond due to the end-to-end overlapping.

- Atomic orbitals in the sigma bond will be Sp³ and Sp³

- Atomic orbitals in the pi bond would be nil because there is no pi bond.

B) For compound 2;

- the molecular orbital type is sigma and pi bond

-Atomic orbitals in the sigma bond would be Sp² of C and p of O

- The Atomic orbitals in the pi bond will be; p of C and p of O