What is the correct answer? Please

Answer: Diamonds were first discovered and mined in India over 2,400 years ago.

Explanation: Over time, diamonds were found in many other areas around the world, including many in Africa. In today's trade, Africa, Russia, Australia, and Canada produce the most diamonds.

~Wonderopolis

Answer:

Diamonds are formed when under the heat and pressure of the earth's gravity.  Diamonds have to be underground to be formed so they should be underground. Digging to Y11 is deep enough to find diamonds .

Answer:

 24He

Explanation:

When a nuclide is bombarded with alpha particles, we notice an increase in its mass and charge since an alpha particle has a mass of four and a charge of +2. recall that nuclear equations must be balanced. That is, the masses and charges on the left hand six and the right hand side of the nuclear reaction equation must be exactly the same.

Looking at the nuclear reaction at hand, the total mass on the left hand side has to be 246 while the total charge on the left hand side of the equation will be 98. Coming over to the right hand side, the total masses are also found to be the same as a neutron with no charge and a mass of 1 is produced. Hence the nuclear reaction equation is balanced when an alpha particle (helium nucleus) is substituted for X in the equation.

Answer:

24HE

I took the test!

Answer:

Should be A

Explanation:

o advance counterterrorism efforts in other countries

Answer:

D

Explanation:

E2020

Answer:

The molecules in a solid are stuck in a specific structure or arrangement of atoms. The atoms still vibrate and the electrons fly around in their orbitals, but the entire atom will not change its position.

Answer:

grond water

Explanation:

Answer:

b

Explanation:

it is right

Answer:

D working alone

Explanation:

Working alone is the only option that could potentially be a safety hazard; if you have no one watching your back, errors could occur, like dropping glass or burning your hand, and no one is around to help you.

Choices A, B, and C are not correct because those are all good safety standards.

Answer:

The planets themselves are composed of several trillions or quadrillions or more atoms. As far as hard science is concerned, it would be really hard to picture them as electrons. Conclusion: It can be said with a great accuracy that our planets are NOT huge electrons.

Rutherford's experiments showed that the mass of atoms was mostly concentrated in a very small region, with charge equal to the atomic number- the nucleus. He absolutely did not show, nor is it true, that electrons orbit the nucleus as if they were planets. That was a guess people made in trying to figure out how to picture the atom.

(Hope this helps) Sky

Answer:

0.479 M or mol/L

Explanation:

So Molarity is moles/litres of solution...often written as M=mol/L

So here we are given grams of BaCl2 which we have to convert to moles. To convert to moles of BaCl2 we have to divide 63.2 g BaCl2 by molar mass of BaCl2 which is 208.23 g/mol so you get 63.2/208.23 = 0.3035 moles of BaCl2

Second step is converting the 634mL to litres by simply dividing by 1000 because we know 1 litre has 1000ml so 634/1000 = 0.634L

Now we just plug these guys in our molarity formula M=mol/L

M= 0.3035/0.634 = 0.479 M or mol/L

Answer:

Interestingly enough, I'm not getting

0.0341% w/v

either. Here's why.

Start by calculating the percent composition of chlorine,

Cl

, in calcium chloride, This will help you calculate the mass of chloride anions,

Cl

−

, present in your sample.

To do that, use the molar mass of calcium chloride, the molar mass of elemental chlorine, and the fact that

1

mole of calcium chloride contains

2

moles of chlorine atoms.

2

×

35.453

g mol

−

1

110.98

g mol

−

1

⋅

100

%

=

63.89% Cl

This means that for every

100 g

of calcium chloride, you get

63.89 g

of chlorine.

As you know, the mass of an ion is approximately equal to the mass of the neutral atom, so you can say that for every

100 g

of calcium chloride, you get

63.89 g

of chloride anions,

Cl

−

.

This implies that your sample contains

0.543

g CaCl

2

⋅

63.89 g Cl

−

100

g CaCl

2

=

0.3469 g Cl

−

Now, in order to find the mass by volume percent concentration of chloride anions in the resulting solution, you must determine the mass of chloride anions present in

100 mL

of this solution.

Since you know that

500 mL

of solution contain

0.3469 g

of chloride anions, you can say that

100 mL

of solution will contain

100

mL solution

⋅

0.3469 g Cl

−

500

mL solution

=

0.06938 g Cl

−

Therefore, you can say that the mass by volume percent concentration of chloride anions will be

% m/v = 0.069% Cl

−

−−−−−−−−−−−−−−−−−−−

I'll leave the answer rounded to two sig figs, but keep in mind that you have one significant figure for the volume of the solution.

.

Explanation:

Answer:it is D

Explanation: it is only one that makes sense

"Typical nonmetals have a dull, coloured or colourless appearance; are brittle when solid; are poor conductors of heat and electricity; and have acidic oxides." - Wikipedia

Answer:

all of them except number 2

Explanation:

Answer:

1,3,4,5  the other perosn is correct

Explanation: That what my quiz said

Answer:

5.9 kg  

Explanation:

We must work backwards from the second step to work out the mass of oxygen.

1. Second step

Mᵣ:                                     55.84

            Fe₂O₃ + 3CO  ⟶  2Fe  +  3CO₂

m/kg:                                    7.0

(a) Moles of Fe

[tex]\text{Moles of FeO} = \text{7000 g Fe} \times \dfrac{\text{1 mol Fe}}{\text{55.84 g Fe}} = \text{125 mol Fe}[/tex]

(b) Moles of CO

[tex]\text{Moles of CO} = \text{125 mol Fe} \times \dfrac{\text{3 mol CO}}{\text{2 mol Fe}} = \text{188 mol CO}[/tex]

However, this is the theoretical yield.

The actual yield is 72. %.

We need more CO and Fe₂O₃ to get the theoretical yield of Fe.

(c) Percent yield

[tex]\begin{array}{rcl}\text{Percent yield} &=& \dfrac{\text{ actual yield}}{\text{ theoretical yield}} \times 100 \, \%\\\\ 72. \, \% & = & \dfrac{\text{188 mol}}{\text{actual yield}} \times 100 \,\%\\\\0.72 &= &\dfrac{\text{188 mol}}{\text{actual yield}}\\\\\text{Actual yield} & = & \dfrac{\text{188 mol}}{0.72}\\& = & \textbf{261 mol}\\\\\end{array}[/tex]

We must use 261 mol of CO to get 7.0 kg of Fe.

2. First step

Mᵣ:                32.00

            2C   +  O₂   ⟶  2CO

n/mol:                             261

(a) Moles of O₂

[tex]\text{Moles of O}_{2} = \text{261 mol CO} \times \dfrac{\text{1 mol O}_{2}}{\text{2 mol CO}} = \text{131 mol O}_{2}[/tex]

(b) Mass of O₂

[tex]\text{Mass of O}_{2}= \text{131 mol O }_{2} \times \dfrac{\text{32.00 g O}_{2}}{\text{1 mol O}_{2}} = \text{4180 g O}_{2}[/tex]

However, this is the theoretical yield.

The actual yield is 71. %.

We need more C and O₂ to get the theoretical yield of CO.

(c) Percent yield

[tex]\begin{array}{rcl}71. \, \% & = & \dfrac{\text{188 mol}}{\text{actual yield}} \times 100 \,\%\\\\0.71 &= &\dfrac{\text{4180 g}}{\text{actual yield}}\\\\\text{Actual yield} & = & \dfrac{\text{4180 g}}{0.71}\\\\& = & \text{5900 g}\\& = & \textbf{5.9 kg}\\\end{array}[/tex]

We need 5.9 kg of O₂ to produce 7.0 kg of Fe.

Answer:

Explanation:

Soap breaks up the oil into smaller drops, which can mix with the water. It works because soap is made up of molecules with two very different ends. One end of soap molecules love water - they are hydrophilic. The other end of soap molecues hate water - they are hydrophobic.

Answer:

C. Its polar end mixes with the water so it can be washed away.

Explanation:

Just took test

Answer:

The answer is NaOH

Explanation:

Strong bases are characterized by the fact that they dissociate completely in an aqueous solution. In this case, sodium hydroxide, NaOH, is classified as a strong base because it dissociates completely in an aqueous solution to form sodium cations, Na+, and hydroxide anions, OH−. Also, it is strong because it totally breaks in its ion. And the base which breaks totally in its atom called the strong base and which doesn't it that is a weak base.

Answer:

NaOH

Explanation:

Got it right in the test. Please mark as brainliest

Answer:

The Eocene Period is experiencing net gain in energy while Cryogenian Period is experiencing a net loss in energy.

Explanation:

In Eocene Period, the population of mammals such as horses , whales and bats etc were high due to the presence of high amount of food and good atmospheric condition such as high temperature while the population of animals were low in Cryogenian Period due to the presence of very low temperature which experiencing loss of energy. Most of area of the earth consist of icy desert.

Answer:

1- Dropping a sliced orange into a vat of Sodium Dydroxide

Explanation:

The other answers (2-4) are only physical changes that don't change any chemical compositions.

Answer:

The correct ones are:

|

|||

|V

V

Explanation:

Answer:

1 for and 5

Ex

Study island

Answer:

2.31M

Explanation:

The following data were obtained from the question:

Mole of K2SO4 = 0.450 mole

Volume of water = 195.0 mL = 195/1000 = 0.195L

Molarity =...?

Molarity is defined as the mole of solute per unit litre of the solution. This can be expressed as:

Molarity = mole /Volume

With the above formula we can calculate the molarity of the K2SO4 solution as follow:

Molarity = mole /Volume

Molarity = 0.450/0.195

Molarity = 2.31M

Answer:

Greenhouse gases such as carbon dioxide and water vapor make an atmosphere around the earth and make less heat escape

Explanation:

Answer:

b

Explanation:

hope it helps

C. The concentrations of liquid water and water vapor are stable. it describes the fact that liquid water and water vapor are at equilibrium.

Hence, option (c) is correct. The concentration of liquid water and water vapor will become stable.

Learn more about water vapor:

https://brainly.com/question/17259832

Answer:

B) translucent

Explanation:

Light only partially passes through them.

Answer:

Heat energy (Q) = 1.9925 KJ = 2 KJ (Approx)

Explanation:

Given:

Mass of copper (M) = 45 gram

Change in temperature (ΔT) = 71°C - 12°C = 59°C

Specific heat (c) =0.75 j /g*c

Find:

Heat energy (Q) = ?

Computation:

Heat energy (Q) = Mass(M) × Change in temperature (ΔT) × Specific heat (c)

Heat energy (Q) = 45 gram × 59°C × 0.75 j /g*c

Heat energy (Q) = 1991.25 J

Heat energy (Q) = 1.9925 KJ = 2 KJ (Approx)

Answer:

fermentation

Explanation:

The biggest disadvantage of using nuclear power to produce electricity is the nuclear waste must be safely stored for many years.

Nuclear power is the use of nuclear reactions to produce electricity. Nuclear power can be obtained from:

Nuclear reactions produces high amount of energy and many waste materials which are non degradable and will stay in the environment for the long time.

Hence, nuclear waste must be safely stored for many years.

To know more about nuclear power, visit the below link:

https://brainly.com/question/11963586

#SPJ2

Answer:

In the roller coasters the potential energy that is given is the gravitational potential energy, which this energy increases its value as the object moves away from the earth, that is to say, the more height the roller coaster acquires the more gravitational potential energy it will have, and Said train where people usually get on the roller coaster will descend or descend with greater acceleration.

This gravitational potential energy once the mountain begins to descend or descend is converted into kinetic energy

Explanation:

This that we wrote above is considering that the roller coaster does not have curved routes but rectilinear, in the case that it had curved routes, a force would be added in addition to those written that is the centripetal force, it is the same force that appears in the centrifuges or dryers of clothes or the same washing machine. This force, the centripetal force is the force that draws a moving object, in a curvilinear path, towards the center of the curvature.

Answer:

determining how many ozone molecules are lost in the atmosphere

Pls Mark as Brainliest!!! if this helps...

The mole concept The mole concept can be used to determine the number of ozone molecules are lost in the atmosphere.

The mole concept was introduced by Avogadro. The mole is the SI unit of amount of substance. According to Avogadro, one mole of a substance contains 6.02 × 10^23 atoms, ions, molecules etc.

The mole concept is important in many chemical calculations. The mole concept can be used to determine the number of ozone molecules are lost in the atmosphere. (option C)

Learn more: https://brainly.com/question/7287712