What are the names of the two groups of elements known as the rare earth elements? _________ ___and ____________

Answer:

The percentage by mass of element X is 25 %.

The percentage by mass of element Y is 75 %

Explanation:

X + Y ⇒ XY

3.5 g of element X + 10.5 g of element Y = 14g in total

⇒Element X : 3.5g / 14g = 0.25 ⇒ x 100 % = 25 %

⇒Element Y : 10.5 / 14 = 0.75 ⇒ x 100 % = 75 %

The percentage by mass of element X is 25 %.

The percentage by mass of element Y is 75 %

The percent by mass of X in the compound is 25%, and the percent by mass of Y in the compound is 75%.

The total mass of the compound formed by elements X and Y is the sum of the masses of X and Y, which is 3.5 g + 10.5 g = 14 g. The percent by mass of an element in a compound is calculated by taking the mass of the element and dividing it by the total mass of the compound, then multiplying by 100% to convert the decimal to a percent.

So, the percent by mass of X is (3.5 g / 14 g) × 100% = 25%. The percent by mass of Y is (10.5 g / 14 g) × 100% = 75%.

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Answer:

mass ratio of A/B is 2:1

Explanation:

Since the mass of box A = 10g

                mass of box B = 5g

   Mass of box C = mass of box A + mass of box

A ratio compares two quantities. To find the ratio of the two boxes:

  Ratio of A to B = [tex]\frac{mass of A}{mass of B}[/tex]

  Ratio of A to B = [tex]\frac{10grams}{5grams}[/tex] = 2

The mass ratio is 2:1 i.e box A has twice the mass of B

Answer:

15?

Explanation:

Cause 10+5 is 15 and that’s all I have

To convert 0.063 liters into milliliters, 0.063 will be multiplied by 1000 which will give 63 milliliters.

The question asks how many milliliters are in 0.063 liters. To convert liters to milliliters, we use the conversion factor that 1 liter is equal to 1000 milliliters. Since we are converting from a larger unit (liters) to a smaller unit (milliliters), we need to multiply.

To find the answer, we multiply 0.063 liters by 1000 milliliters/liter:

Therefore, 0.063 liters is equal to 63 milliliters.

Answer:

9.03 x 10²³ atoms in the pennies

Explanation:

I suspect you want to find the number of atoms that makes up the given moles of the pennies:

Number of moles of pennies = 1.5 moles

Solution:

The mole can be defined as the amount of a substance that contains Avogadro's number of particles i.e 6.02 x 10²³atoms.

 number of atoms = number of moles x 6.02 x 10²³ = 1.5 x 6.02 x 10²³

  number of atoms = 9.03 x 10²³ atoms

Answer:

D. A new substance with properties different from either of the liquids was formed.

Explanation:

This is a simple chemical reaction. When chemical reactions occur, bonds are simply broken and rearranged and new ones formed. Formation of new compounds can be seen and clearly observed. These compounds are completely different in properties from the atoms and compounds that combines to form them.

If they still share the same property in anyway, then, there was only a physical combination of the compounds and this implies the formation of a mixture

Answer:

D. A new substance with properties different from either of the liquids was formed.

The correct option that is the answer for the question is option d

Explanation:

In the given question two liquids of different colours are mixed together. One of them has yellow colour, while the other is colourless on mixing we see that the new substance that is formed is neither yellow nor colourless.

And the mixture that is formed is a substance which is not liquid and solid of red colour and we can conclude, that the mixture form does not retain any property of the elements from which it is made. Hence we can say a new substance with different properties are formed.

Answer:

The ratio of the metal to oxygen is 2:1

Explanation:

Given parameters:

Number of moles of unknown metals = 0.48moles

Number of moles of oxygen = 0.24moles

To find the mole ratio:

We divide the given moles by the smallest values. This gives the simplest form of the two elements:

    Elements                          Unkown metal                Oxygen

Number of moles                      0.48                              0.24

simplest form                          0.48/0.24                   0.24/0.24

                                                       2                                    1

The ratio of the metal to oxygen is 2:1

The mole ratio of an unknown metal to oxygen, given 0.480 moles of the metal and 0.240 moles of oxygen, is 2:1. This ratio was calculated by dividing the number of moles of the metal by the number of moles of oxygen.

The mole ratio of metal to oxygen can be determined by dividing the number of moles of each element by each other. In this case, we are given that there are 0.480 moles of an unknown metal and 0.240 moles of oxygen. To find the mole ratio, we divide the moles of the metal by the moles of oxygen:

Mole ratio = moles of metal / moles of oxygen = 0.480 moles / 0.240 moles = 2:1.

This means for every 2 moles of the metal, there is 1 mole of oxygen, which is the required mole ratio of metal to oxygen.

Fractional distillation is used in the production of alcoholic spirits like brandy or whiskey, where mixtures of water and alcohol are separated into multiple distilled alcoholic products based on their boiling points.

Aside from the refining of crude petroleum into various fuels and oils, another mixture of liquids separated on an industrial scale by fractional distillation is the production of alcoholic spirits, such as brandy or whiskey. In this process, a mixture of water and alcohol is heated, causing the components with lower boiling points (like ethanol) to vaporize first. These vapors rise up the distillation column, condensing at different heights according to their boiling points, and are then collected as separate products. This detailed understanding of fractional distillation illustrates how different substances, due to variations in boiling points, can be extracted from a complex mixture.

Answer: Dependent variable

Explanation:

The dependent variable  in an experiment brings the result of the experiment. The independent variable are the factors that is being controlled by the experimenter.

The dependent variable is basically the aim of the experiment. So, it needs to be measured in order to obtain a result.

The dependent variable is dependent on the independent variable. Hence, to obtain data of the experiment dependent variable is observed.

Answer:

The amount of heat require to melt the gold is 1290 J.

Explanation:

Formula:

Q = m × Lf

Q = heat required to melt the substance

m = mass of given substance

Lf = Latent heat of fusion

Given data:

Lf = 64.5 j/g

m = 20 g

Q = ?

Now we will put the values in formula.

Q = m × Lf

Q =  20 g × 64.5 j/g

Q = 1290 J

The amount of heat require to melt the gold is 1290 J.

Answer:

The amount of heat require to melt the gold is 1290 J.

Explanation:

Answer:

kg, mg. 65.00, 65,000,000. 65.01, 65,010,000. 65.02, 65,020,000. 65.03, 65,030,000. 65.04, 65,040,000. 65.05, 65,050,000. 65.06, 65,060,000.

Explanation:

Answer:

b. data is the information that proves all hypotheses are correct

Explanation:

Data is important to scientific endeavors as it is the information which supports or does not support a certain hypothesis someone has about a certain theory, data will generate further ways to support that theory or oppose it, in both cases the basic resource which a scientific endeavor needs is data

Answer:

On the periodic table, there are two numbers for every element: the atomic number and the atomic weight.

The numbers at the top of the square represents the number of protons present in the atom's nucleus of that element. This is called the atomic number.

For example, the atomic number for the element Krypton is 36. That means that there are 36 protons in the nucleus. If there were not 36 protons in the nucleus of that atom, that would create the atom of a completely different element. For example, if one proton was to be removed from the nucleus of the atom for the element of Krypton that atom will be an atom of the element bromine.

Explanation:

The bottom number found on each element in the periodic table is the atomic mass. This represents the total count of protons and neutrons found in that element's atom. The atomic mass is typically an average value due to the variety of isotopes existing for each element.

The bottom number on each element shown on the periodic table is called the atomic mass. Each element in the periodic table is represented with the atomic number, element symbol, and atomic mass. The atomic number (Z) is displayed above the element symbol, while the atomic mass (A), which is the sum of the number of protons and neutrons in an atom, is displayed below it. For instance, if we look at carbon, we will see its atomic number is six, and its atomic mass is approximately 12.01. This atomic mass is the average mass of all the isotopes of an element, taking into account the relative abundance of each isotope.

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Answer:In the 1st structure, it would have 7 valance electrons, and the 2nd would only have 6.(as shown is the photo)

Answer:

The force you need to apply would be 15 N.

Explanation:

To find the Force you need to apply, you have to use Newton´s second law     (F = m x a).

F = m x a ⇒ F = 5 kg x 3 m/s²⇒ F = 15 N.

The force would be 15 N.

Answer: The force needed is 15N

Explanation:

using the equation F=ma

Where F is the force in Newton

m is the mass in kg

a is the acceleration in m/s^2

F=5*3=15N

Answer:

0.705 g/cm³

Explanation:

Step 1: define density

The (volumetric mass) density of a sample or substance, is this sample or substance its mass per unit volume and can be defined through following formula:

ρ = m/v

with ρ = density (kg/m³)

m = mass of the substance (kg )

v = volume (m3)

Step 2: change datat SI-units

10.0 cm³ = 10^-5 m³

7.05 g = 0.00705 kg

ρ = 0.00705 kg / 10^-5 m³  = 705 kg / m³

To convert this to g/cm³ we have to divide by 1000

ρ = 0.705 g/cm³

To control this we calculate 7.05g / 10cm³ = 0.705 g/cm³

The desnity of the alcohol is 0.705 g/cm³

The electronic configuration of Be(beryllium) is [tex]1s^{2} 2s^{2}[/tex], C = 2 and D = 2.

The placement of electrons all around nuclei of a specific atom or molecule would be known as its electronic configuration.

The Be atom is a kind of atom which have 4 electrons.

The electronic configuration of Be is  [tex]1s^{2} 2s^{2}[/tex]. Therefore, C = 2 and D = 2.

To know more about  electronic configuration

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Answer:

Answer is: zinc nitrate (Zn(NO₃)₂) is strong electrolyte.

Explanation:

Ions are good conductors of electric current in the solution. Strong electrolytes are strong acids (for example hydrochloric acid HCl), strong bases (sodium hydroxide NaOH, for example) and soluble ionic salts (in this example, zinc nitrate).

Answer:

Metamorphic rock is made by a mixture of heat and pressure

Explanation:

Answer:

The answer is the toaster and the room heater.

Explanation:

Both objects are powered by electricity in order to heat things, such as bread and people.

Hope this helps!

Answer:

Option (2)

Explanation:

The process by which one type of energy is transformed into another type is known as the conversion of energy . The changing of electrical energy to thermal energy is an example of energy conversion.

The room heaters are used to heat the room, maintaining a certain room temperature, and a toaster is used to make toasts. Both the room heater and the toaster are the two things from the given options that are used widely and it converts energy, from electrical to thermal energy.

Thus, the correct answer is option (2).

Answer:

10.836 × 10∧23 atoms

Explanation:

The mole is the unit of amount in chemistry. We know that

1 mole of silicon = 6.02× 10∧23 atoms

The number 6.02× 10∧23 is called Avogadro's number.

Definition:

" Avogadro's number is the number of molecules atoms or ions in one gram molecule of a compound, one gram atom of an element or one gram ions of a substance"

For example:

1 g of hydrogen = 1 mole of hydrogen = 6.02× 10∧23 atoms of hydrogen

18 g of water= 1 mole of water= 6.02× 10∧23 molecules of water

Given data:

moles of sulfur= 1.8 mol

number of atoms= ?

Solution:

one mole of silicon=  6.02 × 10∧23

1.8 × 6.02× 10∧23 = 10.836 × 10∧23 atoms

Explanation:

According to the mole concept there are [tex]6.022 \times 10^{23} atoms[/tex] present in 1 mole of a substance.

Mathematically,    1 mole = [tex]6.022 \times 10^{23}[/tex] atoms or molecules

Therefore, number of atoms of silicon present in 1.8 mol of silicon are as follows.

          [tex]1.8 mol \times 6.022 \times 10^{23}}atoms /mol[/tex]

                 = [tex]10.83 \times 10^{23}[/tex] atoms

Thus, we can conclude that there are [tex]10.83 \times 10^{23}[/tex] atoms of silicon are present in 1.8 mol of silicon.

Answer:

[tex]$\Delta x . \Delta p \geq \frac{h}{4 \pi}$[/tex]

∆x is the Uncertainty in the position of the particle

∆p is the Uncertainty in the momentum of the particle

[tex]$\Delta p=\frac{h}{4 \pi \times m \times \Delta x}$[/tex]

[tex]$=\frac{6.626 \times 10^{-34} \mathrm{kgm}^{2} s^{-1}}{4 \times 3.14 \times 9.109 \times 10^{-31} \mathrm{kg} \times 471 \times 10^{-12} \mathrm{m}}$[/tex]

[tex]$=\frac{6.626 \times 10^{-34} \mathrm{ms}^{-1}}{53887 \times 10^{-43}}$[/tex]

[tex]=1.23\times10^5 ms^{-1}[/tex] is the answer

Answer:

Sr²⁺

Explanation:

Krypton has 36 electrons and an electron configuration of 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6. An ion with a charge of 2+ and 36 electrons is Sr²⁺. Since it has the same amount of electrons, Sr²⁺ also has an electron configuration of 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6.

The formula of the ion is Sr²⁺

From the periodic table, we understood that Krypton (Kr) has 36 electrons.

From the question given above, we were told that the ion has the same electronic configuration as krypton. Thus,

The ion also have 36 electrons.

Finally, we shall determine the number of protons in the ion in order to determine the element that form the ion and also the symbol of the element.

Electrons in the ion = 36

Charge on ion = +2

2 = Proton – 36

Collect like terms

Proton = 2 + 36

Considering the period table, the element with 38 protons (i.e atomic number of 38) is strontium with symbol Sr.

Therefore, the formula of the ion with the same electron configuration as krypton is Sr²⁺

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Answer:

Explanation:

Dissolving is when a soluble solute is added to a solvent. The solvent surrounds the solutes and makes a solution of it. The process of dissolving is known as dissolution. For a substance to be able to dissolve in a solvent, they must both have similar properties. It is generally known that like dissolves like. Polar solvents will dissolve polar solutes and vice versa.

Boiling can reverse dissolution process in that, the solvent can reach its boiling point and it wil begin to give out vapours. As more vapours are release, the solutes begin to aggregate and form back.

Answer:

Explanation:

The main advantage of producing more than one prototype at a time is that it gives them the edge in testing different variants of cookies at the same time.

It more like introducing different commodities to see which one would best suit the consumer's needs.

The produce would be able to compare price, quality, value and parameters that can be assumed from the consumption of the cookies side by side. These set of data can then be correlated to see which prototype will give the cutting edge.

Making multiple prototypes at a time saves time, allows for comparison, and saves costs in the long run.

When developing a new product, such as a chocolate chip cookie, making more than one prototype at a time can have several advantages:

Overall, making multiple prototypes simultaneously increases efficiency, allows for better comparison, and helps save costs in the long run.

Answer:

Out of all the six options that we are given option one option four and option five would be correct regarding electronic tools.

Explanation:

Since electronic tools are made with the purpose of calculation that can be made easier and faster. Hence the option that suggest that electronic tools give the answers quickly and clearly should be correct.

Secondary the option that says electronic tools can have a large amount of data is also true. Because large amount of calculations can be carried out using electronic tools easily. And since the data is clear the  data analysis will also be accurate.

Answer:

just summing up what the other person said;

A D and E :)

Explanation:

Answer:

The cell that helps provide the energy for mitosis is Process of cell division that results in to identical daughter cells.

Answer:

C. This is because weathering is when a rock is broken down to smaller bits and destroyed. Hope this helps!

Answer:

the answer is C.) Breakdown of rocks through mechanical or chemical processes.

Explanation:

Answer:

It's an isotope of carbon

Explanation:

Isotopes have the same number of protons and electrons but a different number of neutrons.

Carbon, like we find it on the periodic table, has 6 electrons and protons and also 6 neutrons. ( Carbon has a standard molecular weight of 12: 6electrons + 6 neutrons)

This isotope has 6 electrons but 8 neutrons, so this represents Carbon-14. Which is an isotope of carbon.

The atom with 6 protons or electrons is Carbon. However, the mention of 8 neutrons indicates this is an isotope of Carbon, specifically Carbon-14.

A neutral atom with 6 electrons would also contain 6 protons, as the number of protons and electrons in a neutral atom are equal. The element with 6 protons is Carbon, but the presence of 8 neutrons, not 6 (that is associated with Carbon-12), indicates this is an isotope of Carbon, specifically Carbon-14. It's important to note that isotopes are variations of an element that have different numbers of neutrons.

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Answer:

The inner core

Explanation:

Well, Jaron's tunneling machine would find it quite impossible to even penetrate the crust.

Our dynamic earth is arranged in concentric layers with each shell at varrying physical state and chemical properties.

As we go down the earth, the temperature and pressure increases significantly. The innermost layer of the erth is the inner core and it is expected that the temperature and pressure here should be the greatest. The pressure in the inner core is so great that the materials that were supposed to be in molten form exists as solid in there.

Answer:The inner core

Explanation:

Answer:

Explanation:

"Three hundred ten million, seven hundred sixty-three thousand, one hundred thirty-six".

Answer:"Three hundred ten million, seven hundred sixty-three thousand, one hundred thirty-six".

Explanation: