Which nuclear equation represents a spontaneous decay?

Answer: There are [tex]16.14 \times 10^{23}[/tex] atoms of hydrogen are present in 40g of urea, [tex](NH_{2})_{2}CO[/tex].

Explanation:

Given: Mass of urea = 40 g

Number of moles is the mass of substance divided by its molar mass.

First, moles of urea (molar mass = 60 g/mol) are calculated as follows.

[tex]Moles = \frac{mass}{molar mass}\\= \frac{40 g}{60 g/mol}\\= 0.67 mol[/tex]

According to the mole concept, 1 mole of every substance contains [tex]6.022 \times 10^{23}[/tex] atoms.

So, the number of atoms present in 0.67 moles are as follows.

[tex]0.67 mol \times 6.022 \times 10^{23} atoms/mol\\= 4.035 \times 10^{23} atoms[/tex]

In a molecule of urea there are 4 hydrogen atoms. Hence, number of hydrogen atoms present in 40 g of urea is as follows.

[tex]4 \times 4.035 \times 10^{23} atoms\\= 16.14 \times 10^{23} atoms[/tex]

Thus, we can conclude that there are [tex]16.14 \times 10^{23}[/tex] atoms of hydrogen are present in 40g of urea, [tex](NH_{2})_{2}CO[/tex].

Explanation:

The boiling point of alcohols also increase as the length of hydrocarbon chain increases

The boiling point of alcohols also increase as the length of hydrocarbon chain increases.

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Answer:

T = 82 K

Explanation:

The computation of the final temperature is shown below;

Given that

T_0 denotes the initial temperature of the gas i.e. 74 K

T denotes the final temperature of the gas = ?

n denotes number of moles of monoatomic gas i.e. 1.00 mol

R denotes universal gas constant = 8.314

c denotes the heat capacity at constant volume i.e.

= (1.5) R = (1.5) (8.314)

= 12.5

Q denotes the Amount of heat absorbed i.e 100 J

We know that

Amount of heat absorbed is provided as

Q = n c (T - T_0)

100 = (1) (12.5) (T - 74)

T = 82 K

Answer:

B. 4.32 x 10-19 J is correct via a p e x

Explanation:

Answer:

The main function of nucleic acid is It stores lipids inside the proteins.

Nucleic acids are large biomolecules that play essential roles in all cells and viruses. A major function of nucleic acids involves the storage and expression of genomic information. Deoxyribonucleic acid, or DNA, encodes the information cells need to make proteins. A related type of nucleic acid, called ribonucleic acid (RNA), comes in different molecular forms that play multiple cellular roles, including protein synthesis. 

Nucleic acids are made of nitrogen-containing bases, phosphate groups, and sugar molecules. Each type of nucleic acid has a distinctive structure and plays a different role in our cells. Researchers who first explored molecules inside the nucleus of cells found a peculiar compound that was not a protein or a lipid or a carbohydrate. It was new.  The discovery of this molecule — nuclein, which upon further understanding became nucleic acid — set in motion the eventual discovery of DNA.

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Explanation:

H=mc×∆©

9.86=m×0.902×(30.5-23.2)

m=1.5

Explanation:

The specific heat of a substance is the amount of heat required to raise the temperature of 1 gram of the substance by 1 degree Celsius. The formula for calculating the heat absorbed or released by a substance is `q = mcΔT`, where `q` is the heat absorbed or released, `m` is the mass of the substance, `c` is the specific heat of the substance, and `ΔT` is the change in temperature.

In this case, we can use this formula to solve for the mass of the aluminum sample. We know that `q = 9.86 J`, `c = 0.902 J/g°C`, and `ΔT = 30.5°C - 23.2°C = 7.3°C`. Plugging these values into the formula, we get:

`9.86 J = m * 0.902 J/g°C * 7.3°C`

Solving for `m`, we find that the mass of the aluminum sample is approximately `1.5 g`, rounded to 2 significant figures.

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Answer:

5 Acids

Chemical

- Hydrochloric acid in gastric juice

- Sulphuric acid

- Nitric acid

- Uric acid

- Acetic acid

Household

- Vinegar

- Lemon

- Milk

- Batteries

- Soft drinks

5 Alkali

Household

- Dishwashwer soaps

- Detergents

- Toothpaste

- Oven cleaner

- Alkaline batteries

- Sodium bicarbonate

Chemicals

- Sodium hydroxide or lye

- Calcium carbonate (limestone)

- Ammonium hydroxide

- Calcium hydroxide

Answer:

covalent

valence electrons

Explanation:

The attraction between two atoms that share a pair of valence electrons is known as a covalent bond. The nuclei of both atoms are drawn to the shared electrons. This results in a molecule with two or more atoms. Covalent bonds are formed solely between nonmetal atoms.

Between atoms of the same element or between atoms of different elements, covalent bonds can form. A new substance termed a covalent compound is formed when atoms of various elements create covalent bonds.

Answer:

9g

Explanation:

moles O2 = mass / Mr = 12 / 2(16.0) = 0.375

ratio O2 : NO = 5:4

moles NO produced = 0.375 * 4/5 = 0.3

mass NO = Mr * mol = (14.0+16.0) * 0.3 = 9g

The Grams of NO is produced if 12g of O2 is combined with excess ammonia is 80 gram.

The full form of NO is nitrogen oxide Nitrogen belong to the 15th group of the periodic table with molar mass of 14 and oxygen belong to the 16th group of the periodic table.

In the given their are 4 molecules of each nitrogen and oxygen and mass of O2 is given whereas, mass of nitrogen for 4 molecule will be 56 gram.

Grams of NO = 14 × 4 + 12 × 2

Grams of NO = 80 grams.

Therefore, the mass of NO for the given reaction is combined with excess ammonia is 80 gram.

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Answer:

Fraction ionic = 0.43

Explanation:

To solve this question, we must, as first, find the fraction of the bond that is covalent using the equation:

Fraction Covalent = exp (-0.25*(Enitride - EAl)²)

Fraction covalent = exp (-0.25*(3.0- 1.5)²)

Fraction covalent = exp (-0.25*2.25)

Fraction covalent = exp (-0.5625)

Fraction covalent = 0.57

As:

1 = Fraction Covalent + Fraction Ionic:

Fraction ionic = 1 - 0.57

Fraction ionic = 0.43

Answer:

There are 0.195 moles.

Explanation:

1 mol of any gas under STP (meaning 1 atm and 273 K) will occupy 22.4 liters.

With the information above in mind, we can calculate how many moles will occupy 4.38 liters:

In 4.38 liters of a gas at STP there will be 0.195 moles.

Answer:

hkj

Explanation:

Answer: 6.0g x 1 mol/18.02g x 40,65 kJ/mol which is D

Explanation: Just did

The water vapors change from vapor into water in condensation. The energy released by 6 gm of water is 6.0 g x 1 mol/18.02 g x 40.65 kJ/mol. Thus, option D is correct.

The heat of vapourization is the latent heat or enthalpy needed by the liquid to get converted into the vapor or the gaseous phase of the matter. It can be used to determine the energy released or absorbed by the substance.

The heat of vapourization of water is 40.65 kJ/mol, and its molar mass is 18.02 moles.

So, the energy released for the water when it is condensed into vapors will be,

6.0 g x 1 mol/18.02 g x 40.65 kJ/mol

Therefore, the heat of vapourization determines the amount of energy released.

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Answer:

a endothermic, absorbed

Answer:  the area of the telescope lens is \textit{0,08507 ft}

Explanation: Happy I could help!

Answer:

The heat capacity of the metal underneath the gold is 0.431 J/g°C

Explanation:

Using the formula as outlined in the image:

Q = m × c × ∆T

Where;

Q = amount of heat energy (J)

m = mass of substance (g)

c = specific heat capacity (J/g°C)

∆T = change in temperature (°C)

According to the information in this question;

Q = 503.9J

m = 23.02g

c = ?

∆T = 74°C - 23.2°C = 50.8°C

Using Q = m × c × ∆T

c = Q ÷ m∆T

c = 503.9 ÷ (23.02 × 50.8)

c = 503.9 ÷ 1169.42

c = 0.431 J/g°C

From the above heat capacity of the metal underneath the gold, it is obvious that the metal is not pure gold (c = 0.129J/g°C)

Answer:

119.5 J

Explanation:

First we calculate the temperature difference:

Then we can calculate the heat released by using the following formula:

Where q is the heat, Cp is the specific heat, ΔT is the temperature difference and m is the mass.

We input the data:

Answer:

H

Explanation:

UMMM H2O .. im assuming the H missing

Answer:

0.812 L

Explanation:

As this is a dilution process problem, we can solve it by using the C₁V₁ = C₂V₂ formula, where in this case:

We input the data:

And solve for V₁:

This means that 0.812 L of concentrated perchloric acid should be diluted to a final volume of 1.90 L.

Answer: look at the explanation and try to work it

Explanation: in contrast, our atmosphere blocks most ultraviolet light (UV) and all X-rays and gamma-rays from reaching the surface of Earth. Because of this, astronomers can only study these kinds of light using detectors mounted on weather balloons, in rockets, or in Earth-orbiting satellites.

We know that [OH⁻] * [H⁺] = 10⁻¹⁴

plugging the value of [H⁺]

[OH⁻] * 1.2 * 10⁻³ = 10⁻¹⁴

[OH⁻] = 10⁻¹⁴ * (10³/1.2)

[OH⁻] = 833.3 * 10⁻¹⁴

[OH⁻] = 8.33 * 10⁻¹²

Answer:

~4,317.5 moles of Silicon

Explanation:

Using Avogadro's contant we know that:

1mole = 6.022 x 10^23 atoms

So,to calculate the number of moles in 2.60 x 10^27 atoms of Silicon:

=(2.60 x 10^27 x 1)/(6.022 x 10^23)

~4,317.5 moles of Silicon

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Answer:

[tex](24 \times 2) \: g \: of \: magnesium \: reacts \: with \: (16 \times 2) \: g \: of \: oxygen \\ 2.64 \: g \: of \: magnesium \: will \: react \: with \: ( \frac{2.64 \times 16 \times 2}{24 \times 2} ) \: g \\ = 1.76 \: g \: of \: oxygen[/tex]

Answer:

Hello, I was doing this and from my caluclations it should be :

Explanation:

3 Moles.

The three moles of MgCO3 are present in 252.939 grams of MgCO3.

So, option B is correct one .

The molar mass of substance is equal to mass of one mole of  that substance.

Example: Molar mass of MgCO3 is equal to mass of one mole of MgCO3.

Molar mass of Mg = 24.305 u

Molar mass of C = 12.011 u

Molar mass of O = 15.999 u

Molar mass of MgCO3 = Molar mass of Mg + Molar mass of C + Molar mass of O*3

Molar mass of MgCO3 = 24.305 + 12.011  +  15.999 * 3

Molar mass of MgCO3 = 84.3139 gram

Molar mass of  MgCO3 contain  84.3139 gram

So, 252.939 grams of MgCO3 = 252.939 grams/84.3139 gram

252.939 grams of MgCO3 = 2.999 moles

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+HF is the answer

Explanation:

Answer:

El cloruro de litio se utiliza para fabricar litio metálico. El cloruro de litio se funde y electroliza. Esto produce litio metálico líquido.

Explanation:

sowwy si mi español es malo

Answer:

give him brainliest

Explanation:

Answer:

D. Fundamental forces acting between two pieces of matter

Answer:

D. Fundamental forces acting between two pieces of matter

Answer:

[tex]r=25M^{-1}s^{-1}[A]^2[/tex]

Explanation:

Hello there!

In this case, according to the given information for this chemical reaction, it is possible for us to set up the following general rate law and the ratio of the initial and the final (doubled concentration) condition:

[tex]r=k[A]^n\\\\\frac{r_1}{r_2} =\frac{k[A]_1^n}{k[A]_2^n}[/tex]

Next, we plug in the given concentrations of A, 0.2M and 0.4 M, the rates, 1.0 M/s and 4.0 M/s and cancel out the rate constants as they are the same, in order to obtain the following:

[tex]\frac{1.0}{4.0} =\frac{0.2^n}{0.4^n}\\\\0.25=0.5^n\\\\n=\frac{ln(0.25)}{ln(0.5)} \\\\n=2[/tex]

Which means this reaction is second-order with respect to A. Finally, we calculate the rate constant by using n, [A] and r, to obtain:

[tex]k=\frac{r}{[A]^n} =\frac{1.0M/s}{(0.2M)^2}\\\\k=25M^{-1}s^{-1}[/tex]

Thus, the rate law turns out to be:

[tex]r=25M^{-1}s^{-1}[A]^2[/tex]

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