Please help me its balancing the equation

Answer:

0.208 mol B

Explanation:

There are 6.02 × 10^23 atoms in one mole of a substance, according to Avagadro's law.

According to this question, there are 1.25 x 10^23 atoms of Boron. This means that the number of moles in the Boron atom can be calculated thus:

number of moles (n) = number of boron atoms (nA) ÷ Avagadro's number

n = 1.25 x 10^23 ÷ 6.02 × 10^23

n = 0.2076 × 10^(23-23)

n = 0.208 × 10^0

n = 0.208 × 1

n = 0.208 moles of Boron

Answer: Polar bond

Explanation:

The number of atoms : N = 2.709 x 10⁴⁶

Given

4.5 x 10²² moles of CO₂

Required

The number of atoms

Solution

The mole is the number of particles(molecules, atoms, ions) contained in a substance  

1 mol = 6.02.10²³ particles

Can be formulated

N=n x No

N = number of particles

n = mol

No = Avogadro's = 6.02.10²³

Input the value :

N = 4.5 x 10²² x 6.02 x 10²³

N = 2.709 x 10⁴⁶

Answer:

Trees change over time.

Explanation:

In the summer, trees thrive on the nutrients the sunlight gives them. In the winter, their leaves change colors and they start to perish. Then, with a little bit of sunlight ad water, they can thrive again. Stars also start to perish at some point, but they do not thrive again. They continue perishing until they implode.

Answer:

something that triggers

Explanation:

a catalyst helps move a reaction along

A catalyst shows some specificity in its action. It speeds up only a spontaneous reaction. The best definition of catalyst is something that triggers. The correct option is C.

A substance which increases the rate of a chemical reaction without itself undergoing any permanent change chemically or quantitatively is defined as the catalyst and the phenomenon is called catalysis.

It is believed that a catalyst actually participates in the chemical reaction that is speeds up. It forms temporary bonds with the reactants yielding an intermediate activated complex.

A typical example of catalyst is iron (Fe) which is used in the Haber process for the manufacture of ammonia. The catalyst is recovered unchanged in amount and chemical composition at the end of the reaction.

In most cases, a small amount of a catalyst can speed up reaction between large amounts of reactants. A catalyst shows maximum efficiency at optimum temperature.

Thus the correct option is C.

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Explanation:

(a) write a balanced equation for the reaction

CaCO3 + HCl --> CaCl2 + H2O + CO2

The balanced equation is given as;

CaCO3 + 2HCl → CaCl2 + H2O + CO2  

(b) when the reaction was complete, 800 mL of carbon dioxide gas was collected. How many moles of calcium carbonate were used in the creation?

From the balanced reaction;

1 mol of CaCO3 reacts to produce 1 mol of CO2

1 mol of CO2 = 22.4 L of CO2

This means;

1 mol of CaCO3 reacts to produce 22.4L  of CO2

x mol would produce 800ml (0.8 L) of CO2

1 = 22.4

x = 0.8

x = 0.8 * 1 / 22.4 = 0.0357 mol

(c) How many grams of CaCO3 were used?

Mass = Number of moles * Molar mass

Molar mass of CaCO3 = 100.0869 g/mol

Mass = 0.0357 mol * 100.0869 g/mol = 3.57 g

(d) If there was another contaminant in the sample that was not un reactive, would this have caused the percent yield of carbon dioxide to be higher, lower, or the same, explain your answer.

The same

An un reactive contaminant in the sample is most likely a catalyst. Catalysts only affect the rate of reaction. They do not affect yields of products.

Answer:

what is the displacement

Explanation:

Answer:

-1

Explanation:

The number of molecules of Nitrogen dioxide : = 4.816 x 10²⁴

Given

4 moles of Oxygen(O2)

Required

The number of molecules

Solution

Reaction

2NO + O2 ⇒ 2NO2

From the equation, mol NO2 :

= 2/1 x mol O2

= 2/1 x 4 moles

= 8 moles

The number of molecules :

= 8 x 6.02 x 10²³

= 4.816 x 10²⁴

Heat is transferred by energy waves moving through space. Explanation: According to research: Radiation is the transfer of heat energy through space by electromagnetic radiation. Most of the electromagnetic radiation that comes to the earth from the sun is invisible

Please give brainiest if possible, I kinda need it. Thnx!

Answer:

the transfer of energy through space is called radiation. through radiation there is no direct contact between heat source and object. sunlight radiation warms the earth's surface; radiation can also come from fires.

Answer:

(500.0 g PbCl2) / (278.1164 g PbCl2/mol) × (6.022 × 10^23 f.u./mol) =  

1.083 × 10^24 formula units

Explanation:

2 covalent bonds

2 pairs or 4 electrons

Answer:

All elements are neutral

Explanation:

The plum pudding model of the atom indicated that all elements are neutral. The model was proposed by J.J Thomson after he conducted his experiment on the gas discharge tube.

From the experiment he discovered electrons which he called cathode rays.

Therefore, he suggested the plum pudding model of the atom.

The model describes negatively charge sphere surrounded by positive charges to balance them.

Answer:

The melting temperature of a solid is generally considered to be the same as the freezing point of the corresponding liquid; because a liquid may freeze in different crystal systems and because impurities lower the freezing point, however, the actual freezing point may not be the same as the melting point.

Answer:

[tex]\boxed {\boxed {\sf A. \ 54 \ grams }}[/tex]

Explanation:

To convert from moles to grams, we must use the molar mass.

Recall that water's molecular formula is H₂O. It contains hydrogen and oxygen. Look up the two elements masses on the Periodic Table.

Now, use these masses to find water's mass. The subscript of 2 tells us there are 2 atoms of hydrogen, so we multiply hydrogen's mass by 2 and add oxygen's.

Use the molar mass as a ratio.

[tex]\frac{18.015 \ g \ H_2 O}{ 1 \ mol \ H_2 O}[/tex]

Multiply by the given number of moles.

[tex]3 \ mol \ H_2O*\frac{18.015 \ g \ H_2 O}{ 1 \ mol \ H_2 O}[/tex]

The moles of water will cancel.

[tex]3 *\frac{18.015 \ g \ H_2 O}{ 1 }[/tex]

[tex]3 *{18.015 \ g \ H_2 O}[/tex]

[tex]54.045 \ g \ H_2O[/tex]

Round to the nearest whole number. The 0 in the tenth place tells us to leave the number as is.

[tex]54 \ g \ H_2O[/tex]

There are about 54 grams of water in 3 moles.

Answer:

54 grams

Explanation:

First step is to find what one mole of water is in grams.

Water is H2O so that means we have two moles of Hydrogen.

H - 2 grams (on periodic table)

We have one mole of Oxygen.

O - 16 grams (on periodic table)

Add 2 and 16 to get 18 total grams in one molecule of H2O

Now multiply 3 times 18 to know how many grams in 3 moles of H2O

You end with

3x18=54 grams

Answer: There are 3.99 .

Explanation:

Answer:

199.26 or with sig figs 2.0 x 10^2

Explanation: you take the # of molecules and divide it by avagadros number which is 6.022141 x 10^23

Answer: It’s 2.9 moles

Explanation:

Answer:

b) 3

Explanation:

i got it right

Answer:

gas and liquid

Explanation:

Number of Silver atoms : N = 7.8 x 10²² atoms

Given

mass of bracelet : 13.94 g

Required

Number of atoms

Solution

Assuming the bracelet consists entirely of silver

mol of silver :

= mass : molar mass

= 13.94 g : 107,8682 g/mol

= 0.129

Number of atoms :

N = n x No(No = Avogadro's number)

N = 0.129 x 6.02 x 10²³

N = 7.8 x 10²² atoms

Answer:

I think the answer is A - they used X-ray analysis.

Explanation:

Answer:They used X-ray analysis

Explanation:

It’s in the text

Answer:

C

Explanation:

It's simple because there were so many quantitative analysis of error and they didn't had the kind of observations as we have now

Answer:   Because planets do not have nuclear fusion, they do not produce their own light. Instead, they shine with light reflected from a star. When we see planets in the night sky, such as Venus, the so-called "Evening Star," we're seeing reflected sunlight.

Explanation: