A piece of metal has a volume of 30.0cm3 and a mass of 252g. What is its density? what metal do you think this is?

Answer:

As hydrogen is more electronegative than boron, in BH3 the oxidation number of hydrogen should be taken as -1. (E. N. of B = 2.0 & E. N. of H = 2.1)

Suppose, oxidation number of B is x.

So, we can write, x + 3*(-1) = 0

=> x = +3

Therefore, oxidation num

Explanation:

As hydrogen is more electronegative than boron, in BH3 the oxidation number of hydrogen should be taken as -1. (E. N. of B = 2.0 & E. N. of H = 2.1)

Suppose, oxidation number of B is x.

So, we can write, x + 3*(-1) = 0

=> x = +3

Therefore, oxidation num

Vanadium(II) sulfate

Vanadium(III) sulfate is the inorganic compound with the formula V2(SO4)3

Answer:

“Magma” is exclusively found and formed beneath the earth’s surface. Once magma is on or above the surface of the earth it is referred to as “lava.” Magma is typically formed by extreme temperature melting solid rock within the earth. Pressure and rock composition can also affect magma formation. High pressure can help magma be “squeezed” from partially molten rock. Likewise, as rocks are usually composed of different minerals with different melting points, magma formation from rocks is usually only partial and uneven.

Explanation:

Answer:

0.0061650760770388 mole

Answer:

4/15

Explanation:

15/15 - 11/15 = 4/15

If 11/15 is the probability that it'll rain tomorrow, then the rest should be the probability that it'll not rain tomorrow.

Edit : OPTION C is the answer

Option B is the best, Even though the cost is 30 Billion it essentially takes Lesser time to construct. For Plan A, They would have to construct the overground railway and then take a lot of time and effort to create wildlife corridors and then plant trees. Plan B takes much less time compared to plan A and might as well have a lesser impact on the environment!

Answer:

Choice A. [tex]\rm H_{2}[/tex] would be produced at the negative electrode.

Explanation:

Ionic equation for this reaction:

[tex]2\, {\rm K^{+}} + 2\, {\rm Cl^{-}} + {2\, \rm H_{2} O} \to {\rm H_{2}} + {\rm Cl_{2}} + 2\, {\rm K^{+}} + {\rm 2\, OH^{-}}[/tex].

Net ionic equation:

[tex]2\, {\rm Cl^{-}} + 2\, \rm H_{2} O} \to {\rm H_{2}} + {\rm Cl_{2}} + 2\, {\rm OH^{-}}[/tex].

Half-equations:

[tex]2\, {\rm Cl^{-}} \to {\rm Cl_{2}} + 2\, {e^{-}}[/tex].

(Electrons travel from the solution to an electrode.)

[tex]2\, {\rm \overset{+1}{H}_{2} O} + 2\, {e^{-}} \to \overset{0}{\rm H}_{2} + 2\, {\rm O\overset{+1}{H}\!^{-}}[/tex].

(An electrode supply electrons to the solution to reduce some of the [tex]\rm H[/tex] atoms from [tex]\rm H_{2}O[/tex].)

In a DC circuit, electrons always enter the circuit from the negative terminal of the power supply and return to the power supply at the positive terminal.

The negative electrode is connected to the negative terminal of the power supply. Electrons from the power supply would flow into the solution through this electrode.  

This continuous supply of electrons at the negative electrode would drive a reduction half-reaction. In this question, that corresponds to the reduction of water: [tex]2\, {\rm \overset{+1}{H}_{2} O} + 2\, {\rm e^{-}} \to \overset{0}{\rm H}_{2} + 2\, {\rm O\overset{+1}{H}\!^{-}}[/tex]. Hence, [tex]\rm H_{2}[/tex] would be produced at the negative electrode.

Answer:

I think C (synthesis of biological compounds

Explanation:

have a nice day

Answer:

For a given element, the number of postively charged, massive nuclear particles, the number of protons, is fixed. ... Because the number of protons determines Z , the atomic number, which determines the identity of the atom. The nucleus can also contains neutrons, massive, neutrally charged nuclear particles.

Explanation:

Taking into account its definition, the correct answer is option D) Chromatography.

Chromatography is a method that allows the separation, identification and determination of chemical components in complex mixtures. By means of a chromatography it is possible to separate analytes that are very similar to each other in terms of their physico-chemical properties.

For the separation to occur, the principle of selective retention is used, which consists of the different behavior of the components of a mixture on a specific support (such as paper, a gas, a liquid) and a flowing liquid or gaseous phase. through the bracket.

In other words, there is a stationary phase immobilized on a support and a mobile phase that will drag the sample through the stationary phase. During this process, each component of the sample will move according to its own physicochemical characteristics. The general concept will be that those components that prefer the stationary phase are more retained, while those that prefer the mobile phase will move faster.

In summary, the components of the sample are distributed between two phases of different nature, as a consequence of the speed variation that is established when being dragged by a mobile, liquid or gaseous phase, through a stationary, solid or liquid phase.

Finally, the correct answer is option D) Chromatography.

Learn more about chromatography: https://brainly.com/question/15057878?referrer=searchResults

There are 15 sigma bonds in the molecule. These bonds are formed by overlap of atomic orbitals.

There are two kinds of bonds in organic chemistry, sigma bonds and pi bonds. Sigma bonds are formed by end to end or head to head overlap of atomic orbitals.

Pi bonds are formed by side by side overlap of atomic orbitals.

In the compound 4-methyl-pent-2-ene, there are 15 sigma bonds and only one pi bond.

Hence, in the compound  4-methyl-pent-2-ene, there are 15 sigma bonds.

For another definition of sigma and pi bonds see:

https://brainly.com/question/1517505

Answer:

79 g/mol

Explanation:

Mass of unknown metal deposited = 3.137 g - 1.4 g = 1.737 g

Number of moles of metal deposited = 0.022 moles

Since;

Number of moles = reacting mass/molar mass

Molar mass = reacting mass/number of moles

Molar mass = 1.737 g/0.022 moles

Molar mass= 79 g/mol

Answer:

3.72

Explanation:

First you need the volume.

Final level =             43.3

Initial level =            25.0

Change in volume =18.3

So the density = mass / volume

mass = 68.1

vol     = 18.3

density = 68.1 / 18.3

density = 3.72

Answer:

[tex]\boxed {\boxed {\sf 3.72 \ g/mL}}[/tex]

Explanation:

We are asked to find the density of a small object. Density is calculated using the following formula.

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

The mass of the object is 68.1 grams.

The volume was found using water displacement. A known quantity of water was measured out (25.0 mL), then the object was added. The new water level was recorded (43.3 mL). The volume is the difference between the two water levels.

Now we know the mass and the volume, so we can substitute the values into the formula.

[tex]\rho= \frac{ 68.1 \ g }{18.3 \ mL}[/tex]

[tex]\rho = 3.721311475 \ g/mL[/tex]

The original measurements of mass and water levels have 3 significant figures, so our answer must have the same. For the number we found, that is the hundredth place. The 1 in the thousandth place tells us to leave the 2 in the hundredth place.

[tex]\rho \approx 3.72 \ g/mL[/tex]

The density of the small object is approximately 3.72 grams per milliliter.