Explain how the copper could be in the lake sample near the picnic area but not have been detected by this test.

Answer:

+1

Explanation:

The oxidation number of Hydrogen atom is +1. As Nitrogen is more electronegative than Carbon, the oxidation number of Nitrogen is - 3. The Net charge on the compound is zero.

(hope that helps)

Answer:

b???

Explanation:

Answer:

Pretty sure it A.

Explanation:

I just thought that cause what exactly does 'some later time' mean?

Answer:

hmm that is a very tricky question. probably from over flooding with water

Answer:

See explanation

Explanation:

Oxidation half equation;

3Cd(s) + 6OH^-(aq) ------> 3Cd(OH)2(s) + 6e

Reduction half equation;

2MnO4^-(aq) + 8H^-(aq) + 6e --------> 2MnO2(s) + 4H2O(l)

Balanced reaction equation;

3Cd(s) + 6OH^-(aq) + 2MnO4^-(aq) + 8H^-(aq)  ------> 3Cd(OH)2(s) + 2MnO2(s)

Number of electrons transferred = 6

Answer:

Scientists study Earth's interior by studying

seismic waves. Seismic waves are waves of energy that travel

through Earth.

Explanation:

Answer:

it will decrease because there will not be food for all of them and there is very little space for them now so if there is more they will start to fight

Explanation:

there is very little habitat left for panda bears so if there population increases the food and space with be filed

Hello! jamilialves888

I'm glad you asked my name is ✰Tobie✰

And I will help you understand why the population of ⚝pandas ⚝

is decreasing .

-Your answer :βy Tobie

≛So why are pandas going extinct?

One of the main cause is due to the destruction of their own habitat

Since china is a country that is constantly growing their own homes are slowly   being destroyed Since their habitats are becoming destroyed it forces them to live in small unhabitable area .

≛This leads to another problem.....

If they are forced to live in a small area there will be less food...

Since there is a shortage of food that will leave the panda's to slowly starve to death since pandas only eat bamboo they could never be able to live anywhere else....Another reason panda's are going extinct is because they are being hunted for their fur.

ex·tinct

/ikˈstiNG(k)t/

_____________

It means that the species does not exist anymore and

are no longer in existence

Hope this helps!

                                                                                             -Tobie <3

ʕ •ᴥ•ʔ

Answer:

plz I. need a brainliest

Explanation:

I hope you have a good day

Answer:

15-21 is 6

Explanation:

Answer:

A potential

Explanation:

potential energy is a kind of energy which rest or stays in one position

The objects rest on a position has a potential energy. The bow and arrow that was just pulled back but not yet released has energy has potential energy.

The potential energy of an object is generated by virtue of its position at height above the surface. It is the stored form of energy when the object is at rest. Whereas, kinetic energy of an object is generated by virtue of its motion.

When the object starts to move with a speed, its potential energy starts to convert into kinetic energy. Both are dependent on the mass of the object. And these energies are directly proportional to the mass.

Here, the bow and arrow are not moving with a speed they just pulled and stay on a position, so they don't have a net kinetic energy but they possess a potential energy. Hence, option A is  correct.

Find more on potential energy:

https://brainly.com/question/12807194

#SPJ2

Answer:

mushrooms bacteria mold

Explanation:

Answer:

4.1g of Cr will make (317/104) x 4.1 = 12.5g of CrCl3

You divide by the mass of the solution.

Percent by mass is the mass of the solute divided by the mass of the solution, multiplied by 100.

Example:

You dissolve a 4.00 g sugar cube in 350 mL of tea at 80 °C. The density of water at 80 °C is 0.975 g/mL. What is the percent by mass of sugar in the solution?

Solution

Step 1 — Determine mass of the solute.

The solute is the sugar cube. Mass of solute = 4.00 g.

Step 2 — Determine mass of solvent.

The solvent is the 80 °C water. Use the density of the water to find the mass.

mass of solvent = 350 mL ×

0.975

g

1

mL

= 341 g

Step 3— Determine the total mass of the solution

mass of solution = mass of solute + mass of solvent = 4.00 g + 341 g = 345 g

Step 4 — Determine percent composition by mass of the sugar solution.

% by mass =

mass of solute

mass of solution

× 100 % =

4.00

g

345

g

× 100 % = 1.159 %

The percent composition by mass of the sugar solution is 1.159 %.

Calculate the percentage composition of Ca(MnO4)2.

Firstly, we see how many atoms are there for each element in the formula.

Ca= 1 atom

Mn= 2 atoms

O= 8 atoms

Next, we are going to consult our periodic table for the atomic mass of each element.

Ca= 40

Mn= 55

O= 16

Then, we have to find the molar mass for the compound..

Here is the formula for calculating molar mass of an element:

Molar Mass= ( no. of atoms of the element × atomic mass of the element)

Now, we have to calculate the atomic mass of the compound. So using the molar mass formula for an element, we calculate the molar mass for each element then we sum up their molar masses to get the compounds molar mass.

Molar mass (Ca)= 1× 40

(Ca)= 40

Molar mass (Mn)=2×55

(Mn)= 110

Molar mass (O)= 8×16

(O)= 128

Now: Molar mass( compound)= (Ca)+(Mn)+(O)

= 40+ 110 128

= 278

This is everything we need to calculate our percentage composition for each element..

* The example says to find the percentage composition for Ca. So we only find for Ca, Which is already done using the formula and the answer is 14.39%.

To prove that your answer is correct, find the percentage composition for Mn and O as well. Then you add up their percentage compositions.

If you do and you get 100 as your answer, then your percentage compositions are correct.

Why don't you try finding the percentage composition for Mn and O, then add up all the three percentage compositions. If you 100 as their sum, then your percentage composition for each of the elements are correct.

Answer: Denver is named after James W. Denver, a governor of the Kansas Territory. It is nicknamed the Mile High City because its official elevation is exactly one mile (5280 feet or 1609.344 meters) above sea level.

Answer:

The density of copper is 8.9 grams per cubic centimeter.

Explanation:

There is a writing mistake in statement, correct form is written below:

A 124.6 grams sample of copper has a volume of 14 cubic centimeters. What is the density of copper?

Let suppose that mass of the copper sample is distributed uniformly in its volume, then we shall use the following definition of density ([tex]\rho[/tex]), in grams per cubic centimeter:

[tex]\rho = \frac{m}{V}[/tex] (1)

Where:

[tex]m[/tex] - Mass, in grams.

[tex]V[/tex] - Volume, in cubic centimeters.

If we know that [tex]m = 124.6\,g[/tex] and [tex]V = 14\,cm^{3}[/tex], then the density of the sample of copper is:

[tex]\rho = \frac{m}{V}[/tex]

[tex]\rho = 8.9\,\frac{g}{cm^{3}}[/tex]

The density of copper is 8.9 grams per cubic centimeter.

Answer

Plants can respond to the change of season by losing their leaves, flowering, or breaking dormancy. Plants go through seasonal changes after detecting differences in day length.

Explanation:

Answer:

True

Explanation:

DON'T GIVE BRAINLIEST TO THE FILE EXPLOITER!!!!

Answer:

for the first one we need the previous question to be able to answer it. for the second one density and temperature

Explanation:

Answer:  The vapor pressure of the solution at [tex]29^0C[/tex] is 29.86 mm Hg

Explanation:

As the relative lowering of vapor pressure is directly proportional to the amount of dissolved solute.

The formula for relative lowering of vapor pressure will be,

[tex]\frac{p^o-p_s}{p^o}=i\times x_2[/tex]

where,

[tex]\frac{p^o-p_s}{p^o}[/tex]= relative lowering in vapor pressure

i = Van'T Hoff factor = 1 (for non electrolytes)

[tex]x_2[/tex] = mole fraction of solute  

=[tex]\frac{\text {moles of solute}}{\text {total moles}}[/tex]

Given : 9 moles of [tex]NH_3[/tex] are dissolved in 50 L or 50000 ml of water

mass of water = [tex]density\times volume = 1g/ml\times 50000ml=50000g[/tex]  

moles of solvent (water) = [tex]\frac{\text{Given mass}}{\text {Molar mass}}=\frac{50000g}{18g/mol}=2778moles[/tex]

Total moles = moles of solute  + moles of solvent = 9 mol + 2778 mol = 2787  

[tex]x_2[/tex] = mole fraction of solute  

=[tex]\frac{9}{2787}=3.2\times 10^{-3}[/tex]

[tex]\frac{29.96-p_s}{29.96}=1\times 3.2\times 10^{-3}[/tex]

[tex]p_s=29.86mmHg[/tex]

Thus the vapor pressure of the solution at [tex]29^0C[/tex] is 29.86 mm Hg

Answer:

A- Before the mechanic left, the molecules were moving away from each other. When she returned, they were moving around each other.

Explanation:

Brainliest?

Answer:

7.97 moles of neon are present in the canister.

Explanation:

Avogadro's constant or "Avogadro's number" is the number of constituent particles found in the amount of substance in one mole.

In other words, Avogadro's number is the number of particles that make up a substance (usually atoms or molecules) and that can be found in the amount of one mole of said substance. Its value is 6.023*10²³ particles per mole. Avogadro's number applies to any substance.

So, you can apply the following rule of three: if 6.023*10²³ atoms are present in 1 mole, 4.8*10²⁴ atoms are present in how many moles?

[tex]amount of moles=\frac{4.8*10^{24}atoms*1 mole }{6.023*10^{23}atoms}[/tex]

amount of moles= 7.97 moles

7.97 moles of neon are present in the canister.

Answer:

2059.645g Cl

Explanation:

A mole of any element contains 6.022e23 molecules, so we will divide the given amount of molecules by 6.022e23.

3.5e25 / 6.022e23 = 5.81e1

5.81e1 = 58.1 mol Cl

Now that we have found the amount of moles of Chlorine, we will multiply the number of moles by the molar mass of Chlorine, which is 35.45g/mol.

35.45(58.1) = 2059.645g Cl

Answer:

huh,eat wet sand b4heating iron wool??

Answer:

10.58 J/g-°C

Explanation:

To find the specific heat capacity of the metal, you need to know how much heat was lost when it reacted with water.

You know that there are 55.4 g of water, the initial temp. of water is 25°C, and the final temp. (the mixture's temp.) is 63.4°C.

You should also know that the specific heat capacity of water is 4.186 J/g-°C.

Plug this into the equation the q=mcΔT.

q = (55.4 g)(4.186 J/g-°C)(63.4°C - 25°C)

q = 8905.12896 J

If 8905.12896 J was gained by the water, then 8905.12896 J must have been lost from the metal.

You know that there are 23 g of the metal and that its initial temp. is 100°C.

Plug this information into q=mcΔT.

8905.12896 J = (23 g)(C)(63.4°C - 100°C)

C = 10.58 J/g-°C

*When you plug all of this into the calculator, it will result in a negative number but keep in mind that heat was LOST by the metal so 8905.12896 J  is essentially negative. So the negative cancels out.*

Answer:

B. One element changes into another.

Explanation:

We can see from the equation that uranium is changed to thorium and helium. Transmutation is the process by which one element is changed to another through radioactive decay, nuclear bombardment, or other similar processes.

Answer:b

Explanation:

Answer: 120 g

Explanation: