PLEASE HELP ME, 20 POINTS

How many atoms are in 25.00 g of Li.

Question 1 options:

2.393 x 1024 atoms of Li


1.333 x 1023 atoms of Li


2.16 x 1026 atoms of Li


2.17 x 1024 atoms of Li

How many grams is 2.393 x 1024 atoms of Cl

Question 2 options:

70.45 g Cl


140.9 g Cl


140.9 mole Cl


70.45 mole Cl

How many atoms are in 25.00 g of B.

Question 3 options:

1.393 x 1024 atoms of B


1.333 x 1023 atoms of B


2.16 x 1026 atoms of B


2.17 x 1024 atoms of B

How many grams is 2.393 x 1024 atoms of O

Question 4 options:

70.45 g O


140.9 g O


63.58 mole O


63.58 g O

Answer:

Chemical

Explanation:

Answer:

the answer is a.10

Explanation:

in(No/N) = kt

No = 80 mg

N = 10 mg

t = 30 min

solve for k, then

k = 0.693/t1/2

Substitute k from above and solve for t1/2

10 min is correct.

Radioactive element keeps on decaying over the time. Decay of radioactive element always comes under first order kinetics. The element's half-life of decay of 80mg of a radioactive element decays to 10 mg in 30 mins is 10.04 minutes. The correct option is option A.

Half life tells about the time at which the radioactive material decays to half of its initial concentration.

Mathematically, the initial and final amount of radioactive material can be connected as

ln(No/N) = kt

No =initial amount of radioactive decay= 80 mg

N = final amount of radioactive decay=10 mg

t =time taken to decay= 30 min

K= rate constant

ln( 80 mg/10 mg) = k×30 min

0.069min⁻=k

k = 0.693/half life

half life=10.04min

Therefore the element's half-life of decay of 80mg of a radioactive element decays to 10 mg in 30 mins is 10.04 minutes. The correct option is option A.

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The initial temperature of the water and copper is 22.51°C.

Mass of ice m = 14 g

We know, 1g = 0.001 kg

So, m= (14 x 0.001)kg = 0.014kg

Mass of water ml = 300g = (300 x 0.001)kg = 0.3kg

Mass of copper calorimeter m₂ = 200g = (200 × 0.001) kg = 0.21 kg

Specific heat of water s₁ = 4186 \(\frac{J}{kg . C}\)

Specific heat of ice s₂ = 2100 \(\frac{J}{kg.C}\)

Specific heat of copper s₃ = 387 \(\frac{J}{kg.C}\)

Latent heat of fusion of water L = 3.33 x 10⁵ \(\frac{J}{kg}\)

Initial temperature of ice T₁ = - 10°C

Initial temperature of water copper is T₂

Final temperature of the system is T = 18 °C

From equilibrium in heat

Heat gain by ice to become 0°C of ice +0°C of ice become 0 °C of water + 0°C of water become 18°C of water = heat loss by copper and water

 ms₂ (0°-(-10°)) + mL + ms₁ (T -0°) = m₁s₁ (T₂-18°) + m₂s₃ (T2 - 18°)

∴ 0.014 × 2100 × 10 + 0.014 × 3.33 × 10⁵+ 0.014 × 4186 × 18 = 0.3 × 4186 × (T₂- 18 ) + 0.2 × 387 × ( T₂ -18 )

∴ 6010.87 = 1333.2(T₂ - 18)

∴ T₂ - 18 = 6010.87 / 1333.2 = 4.51

∴ T₂ = ( 18 + 4.51 )

∴ T₂ = 22.51° C

So, the initial temperature of the water and copper is 22.51°C.

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Answer:

1/....

Explanation:

If we say acceleration 'a' is inversely proportional to mass 'm', then

a=1/m.

The mass of oxygen gas produced, given that 15.8 g of potassium permanganate is heated until no more oxygen gas is given off is 1.6 g

From the question given, the following data were obtained:

The mass of oxygen gas produced from the reaction can be obtained as follow:

Mass of potassium permanganate = Mass of remaining substance + mass of oxygen

Inputting the given parameters, we have:

15.8 = 14.2 + mass of oxygen

Collect like terms,

Mass of oxygen = 15.8 - 14.2

= 1.6 g

Thus, we can conclude that the mass of oxygen gas produced from the reaction is 1.6 g

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Answer:

atoms in the nucleus

Explanation:

if you read very well

Answer:

uhhh well ig btw what plant

Explanation:

it would be more sunlight to

Answer:

Usually, the cells are round, elongated or spherical. There are also some cells which are long and pointed on both the ends. Such cells exhibit spindle shape. In some cases, the cells are very long.

Explanation:

Hope I helped! Brainliest plz!

Answer:

59.46 g

Explanation:

To answer this question, the molecular weight of ammonium sulfate must be computed.  To accomplish this, the weights of the individual elements must be noted.
N=14.01\(\frac{g}{mol}\)

H=1.01\(\frac{g}{mol}\)

S=32.07\(\frac{g}{mol}\)

O=16.00\(\frac{g}{mol}\)

To compute the molecular weight:

\(2[14.01\frac{g}{mol}+4(1.01\frac{g}{mol})]+32.07\frac{g}{mol}+4(16.00\frac{g}{mol})=132.14\frac{g}{mol}\)

To calculate the mass:

\(0.45 mol(\frac{132.14g}{1mol})=59.463g\)

Answer:

d. 671.6 nm

Explanation:

It is possible to solve the wavelength of a radiation from its frequency -or vice versa- using:

λ = c / f

Where λ is wavelength,

c is speed of light, a constant (2.998x10⁸m/s)

And f is frequency: 4.464x10¹⁴s⁻¹

Replacing:

λ = 2.998x10⁸m/s / 4.464x10¹⁴s⁻¹

λ = 6.716x10⁻⁷m

As 1m = 1x10⁹nm:

6.716x10⁻⁷m * (1x10⁹nm / 1m) = 671.6nm

Right answer is:

Answer:

Winter

Explanation:

I dont know but whatev

Answer:

Winter

Explanation:

The seasonal cycle in the polar and temperate zones of one hemisphere is opposite to that of the other. Therefore, When it is summer in the Northern Hemisphere, it is winter in the Southern, and vice versa.

hope it helps :)

Answer:

1. 1 , 12, 8

2.2,6, 2, 3

3. 2, 3 ,2

4. 2, 1 , 2

we're currently learning this in my chemistry class so I'm pretty familiar with these equations, so i hope these help

Answer:

There is at least 2 ways. First, the isotopes are allowed to heat water into steam, and the steam turns a generator. 2nd, the isotopes are allowed to heat one end of a "thermopile", and the thermopile powers electronics

Hope this helped you!

Answer:

Explanation:

they both break down the earth

Answer:

they all have something to do with the creation of sedimentary rock

Explanation:

Here, 5.70 grams of hydrogen (H2) are produced from 50.7 g of aluminum (Al) in the reaction.

To find the grams of hydrogen (H2) produced from 50.7 g of aluminum (Al) in the reaction:

2Al  +  3H2SO4  →  3H2  +  Al2(SO4)3

First, find the molar mass of Al and H2:

Al: 26.98 g/mol

H2: 2.02 g/mol

Next, convert the given mass of Al (50.7 g) to moles:

50.7 g Al * (1 mol Al / 26.98 g Al) = 1.88 mol Al

Now, use the stoichiometry of the balanced equation to find the moles of H2 produced:

1.88 mol Al * (3 mol H2 / 2 mol Al) = 2.82 mol H2

Finally, convert the moles of H2 to grams:

2.82 mol H2 * (2.02 g H2 / 1 mol H2) = 5.70 g H2

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Explanation:

It to be fossilized, the remains usually to be covered by sediment soon after death. sediment can include the sandy seafloor,lava,and even sticky tar. Over time, minerals in the sediment seep in to remains. The remains become fossilized.

Answer: Aspartame

Explanation:

A wave is a disturbance that travels through space or matter. It transfers energy from one point to another without transferring matter. The two main types of waves are transverse and longitudinal waves.

Transverse waves oscillate perpendicular to the direction of wave travel while longitudinal waves oscillate parallel to the direction of wave travel. The trend of waves refers to the pattern or behavior of the wave as it travels through space or matter. One trend of waves is that they experience reflection, refraction, and diffraction. Waves also demonstrate constructive and destructive interference. Constructive interference occurs when two waves of the same frequency combine to produce a larger wave. Destructive interference occurs when two waves of the same frequency combine to produce a smaller wave. Waves also exhibit diffraction,

which is the bending of a wave as it passes through a small opening or around an obstacle. The degree of diffraction is dependent on the wavelength of the wave in relation to the size of the opening or obstacle. Finally, waves are characterized by their frequency, wavelength, amplitude, and velocity. These characteristics determine how the wave will behave and interact with other waves and matter.

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If you start with 6.03 g of crude sulfanilamide and recrystallize it from ethanol to recover 4.82 g of pure sulfanilamide, the percent recovery is 80.1%.

Sulfanilamide, commonly known as sulfanilamide, is an antibacterial sulfonamide medication. It is an organic molecule made composed of an aniline that has been derivatized with a sulfonamide group.

To calculate the percent recovery, we'll divide the mass of pure sulfanilamide obtained (4.82 g) by the initial mass of crude sulfanilamide (6.03 g) and multiply by 100 to express the result as a percentage:

Percent recovery = (mass of pure sulfanilamide obtained / initial mass of crude sulfanilamide) x 100

= (4.82 g / 6.03 g) x 100

= 80.1%

So, the percent recovery in this case is 80.1%.

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Answer:

\(\boxed {\boxed {\sf v \approx0.295 \ mL}}\)

Explanation:

We are asked to find the volume of a metal cylinder. We are given the mass and the density.

We know that density is the mass per unit volume of a substance. It is found using the following formula.

\(\rho= \frac {m}{v}\)

We know the density is 21.0 grams per milliliter and the mass is 6.20 grams. We substitute these values into the formula.

\(21.0 \ g/mL = \frac{6.20 \ g}{v}\)

We are solving for the volume, so we must isolate the variable v. First, cross multiply. Multiply the first numerator by the second denominator, then the first denominator and the second numerator.

\(\frac {21.0 \ g/mL}{1} = \frac{6.20 \ g}{v}\)

\(21.0 \ g/ mL *v= 6.20 \ g * 1\)

\(21.0 \ g/ mL *v= 6.20 \ g\)

v is being multiplied by 21.0 grams per milliliter. The inverse operation of multiplication is division. Divide both sides of the equation by 21.0 g/mL.

\(\frac {21.0 \ g/ mL *v}{21.0 \ g/mL}= \frac{6.20 \ g }{21.0 \ g/mL}\)

\(v= \frac{6.20 \ g }{21.0 \ g/mL}\)

The units of grams cancel.

\(v= \frac{6.20 }{21.0 mL}\)

\(v=0.2952380952\)

The original measurements of density and mass both have 3 significant figures, so our answer must have the same. For this number, 3 sig fig is the thousandth place. The 2 in the ten-thousandth place tells us to leave the 5.

\(v \approx0.295 \ mL\)

The volume of the metal cylinder is approximately 0.295 milliliters.

Answer

Explanation

NH4Cl will react with AgNO3 to form a precipitate, AgCl according to the following

Noble gases are exceedingly stable and unlikely to form chemical connections since they have minimal inclination to receive or lose electrons, thanks to the complete valence electron shells of these atoms.

Any one of the seven chemical elements that compose Group 18 (VIIa) of the periodic table is referred to as a noble gas. Helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), radon (Rn), and oganesson are the constituent elements (Og). The noble gases are inflammable, tasteless, colorless, and odorless. The term "noble" has long been used in science and alchemy to describe how resistant metals like gold and platinum are to chemical reactions. As their atomic numbers rise, the abundances of the noble gases fall.

German chemist Friedrich E. Dorn discovered radon for the first time in 1900, and in 1904 it was recognized as a member of the noble-gas family. In 1904, the work of Rayleigh and Ramsay was recognized with Nobel Prizes.

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Hello

A chiral carbon atom is an atom that is attached to four different groups of atom. In the 3 structures given, only two atoms have a chiral center.

I'll proceed to draw the structure and indicate the chiral atom below.

If we look at this chiral carbon, we would notice some different in this particular carbn atom and that it is surrounded by 4 different carbon atoms namely

If we carefully look at this, we would see that it is bonded with CH₂, H, NH₂ and COO

In the second structure, we can see that there's no carbon atom that possess this distinctive and unique characteristic of a chiral center.

Lastly, in this compound, we have a carbon atom with one chiral center which is the second carbon atom. Just like in the pervious question above, it is surrounded by CH₂, H, NH₂ and COOH atoms and this makes it a chiral center.

In the question given, only compound 1 and 3 have one chiral carbon atoms.

Answer:

Verdadero.

Explanation:

¡Hola!

En este caso, dado que las propiedades periódicas nos hablan de un comportamiento específico sobre los elementos en la tabla periódica, resulta primeramente necesario recordar que la electornegatividad nos dice que tan fuerte es un elemento para atraer electrones de valencia de otros elementos.

De este modo, inferimos que es verdadero, ya que de hecho la electronegatividad nos define el tipo de enlace, basado en la diferencia de electronegatividades de los elementos enlazados, de acuerdo con la imagen adjunta.

Saludos!

The two basic geologic processes which contributed to the formation of folded mountain ranges like in Glacier National Park include:

This is a geologic process which involve materials in the earth being washed away and transported to other parts by water, wind etc.

In the case of Glacier National Park, ice erodes the mountain thereby resulting in the folding of the sedimentary rocks.

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