Which of the following are observations? Select all that apply.
A. Watching table salt dissolve in waters'
B. Feeling the sensation of ice held in the hand.
C. Smelling ammonia used in a cleaning solution.
D. Hearing a loud bang when a balloon filled with hydrogen gas is ignited.
E. Looking at the readout of a digital scale when measuring reagents for an experiment.

Answer:

128 neutrons

Explanation:

How many neutrons are there in 8 molecules of [tex]^{19} _9 F_2[/tex]?

Step 1: Calculate the number of neutrons in 1 atom of F.

The atomic number (z) of F is 9 and its mass number (A) is 19. We can calculate the number of neutrons using the following expression.

n⁰ = A - Z = 19 - 9 = 10

Step 2: Calculate the number of neutrons in 1 molecule of F₂.

1 molecule of F₂ contains 2 atoms of F. The number of neutrons in  1 molecule of F₂ is:

(8 n⁰/1 atom F) × (2 atom F/1 molecule F₂) = 16 n⁰/1 molecule F₂

Step 3: Calculate the number of neutrons in 8 molecules of F₂

8 molecule F₂ × 16 n⁰/1 molecule F₂ = 128 n⁰

Answer:

Explanation:

Pellet form of NaOH is highly hygroscopic . It absorbs moisture from air and its weight is increased by the time one tries to weigh one gram of it . Moreover it also reacts with carbon dioxide gas of atmosphere to form sodium carbonate .

2 NaOH + CO₂ = Na₂CO₃ + H₂0.

It also increases its weight .

Answer:

Wind and Hydroelectricity can be considered forms of solar energy.

Explanation:

Wind power is a form of solar energy because winds are caused by the heating of the atmosphere by the sun, the rotation of the Earth, and the Earth's surface irregularities. For as long as the sun shines and the wind blows, the energy produced can be harnessed to send power across the grid.

Hydroelectricity is a form of solar energy because Hydropower relies on the water cycle.

The water cycle has three steps:

Solar energy heats water on the surface of rivers, lakes, and oceans, which causes the water to evaporate.

Water vapor condenses into clouds and falls as precipitation—rain and snow.

Precipitation collects in streams and rivers, which empty into oceans and lakes, where it evaporates and begins the cycle again.

Answer:

fertilization i think

Explanation:

because during fertilization process two identicle cell divisions takes place

Answer:

fertilization

Explanation:

edgenuity

Answer:

0.71 gal

Explanation:

Step 1: Given data

Density of Diesel (ρ): 0.839 g/mL

Mass of Diesel (m): 2.3 kg

Step 2: Convert "m" to grams

We will use the relationship 1 kg = 10³ g.

2.3 kg × (10³g/1 kg) = 2.3 × 10³ g

Step 3: Calculate the volume (V) of the Diesel sample

We will use the density formula.

ρ = m/V

V = m/ρ

V = 2.3 × 10³ g/(0.839 g/mL)

V = 2.7 × 10³ mL

Step 4: Convert "V" to L

We will use the relationship 1 L = 10³ mL.

2.7 × 10³ mL × (1 L / 10³ mL) = 2.7 L

Step 5: Convert "V" to gal

We will use the relationship 1 gal = 3.79 L.

2.7 L × (1 gal/3.79 L) = 0.71 gal

Answer:

2.3 kg x1000 g/kg = 2300 g

2300 g x 1 ml/0.839 g = 2741 ml

2741 ml x 1 L/1000 ml = 2.741 L

2.741 L x 1 gal/3.79 L = 0.72 gallons

Explanation:

Answer:

The correct option is (D).

Explanation:

Uncertainty means lack of certainty in any calculations. It is the quantification of doubts after the calculations are done.

In this problem, we need to find the uncertainty in the measurement 0.0035 mg. There are 4 numbers after decimal. It means uncertain digit 1/10000 is the smallest scale division.

Hence, the uncertainty in the measurement 0.0035 mg is +0.0001 mg

Answer:

Number of Significant figures is : 4

Scientific Notation is: 6.3 x 10^-2

EXTRA HELP

Answer:

[tex]V=0.200L[/tex]

Explanation:

Hello,

In this case, since the volumetric capacity of the beaker is 200 cm³, by considering that 1000 cm³ equals 1 L, the liters are then computed via the following unit conversion:

[tex]V=200cm^3*\frac{1L}{1000cm^3}\\ \\V=0.200L[/tex]

Best regards.

Answer:

The answer is

Explanation:

In order to calculate the volume needed we use the formula

[tex]V_2 = \frac{C_1V_1}{C_2} [/tex]

where

C1 is the concentration of the stock solution

V1 is the volume of the stock solution

C2 is the concentration of the diluted solution

V2 is the volume of thevdiluted solution

From the question

C1 = 1.45 M

V1 = 25 mL

C2 = 0.0245 M

So we have

[tex]V_2 = \frac{1.45 \times 25}{0.0245} = \frac{36.25}{0.0245} \\ = 1479.59...[/tex]

We have the final answer as

Hope this helps you

Answer:

a. control everything the cell does

Explanation:

the nucleus is like the brain of the cell

Answer:

344.5764 torr

Explanation:

Molar mass of naphthalene = 128.2g/mol

Mass of naphthalene = 10.60 g

Carbon disulfide:

Molar mass= 76.14g/mol ;

volume = 155mL ;

density = 1.261 g/mL

Vapour pressure = 355.6 torr

Number of moles = mass / molar mass

CS2:

Mass = density × volume

Number of moles = (density × volume) / molar mass

Number of moles = (1.261 * 155) / 76.14 = (195.455 / 76.14) = 2.567 moles of CS2

Number of moles of C8H10:

Number of moles = 10.60 / 128.2 = 0.083 C8H10

Total number of moles :

2.567 + 0.083 = 2.65 moles

Mole fraction of each compound in solution :

CS2 :

2.567 / 2.65 = 0.969

C8H10:

0.083 / 2.65 = 0.031

According to Raoult's:

Psolution = Xsolvent × Posolvent

CS2 = solvent

Xsolvent = Mole fraction of solvent

Posolvent = Vapour pressure of pure solvent

Psolution = 0.969 × 355.6 torr = 344.5764 torr

The vapor pressure of the solution would be as follows:

[tex]344.5764[/tex] torr

Given that,

Vapor pressure of Carbon Disulfide [tex]= 355.6[/tex] torr

[tex]volume = 155mL ;[/tex]

[tex]density = 1.261 g/mL[/tex]

Naphthalene's mass [tex]= 10.60 g[/tex]

Naphthalene's molar mass [tex]= 128.2g/mol[/tex]

Now,

We know that

Number of moles [tex]= mass/molar mass[/tex]

Mass [tex]= density[/tex] × [tex]volume[/tex]

[tex]Number of moles =[/tex] [tex](density[/tex] × [tex]volume) / molar mass[/tex]

So,

Number of moles of Carbon Disulfide [tex]= (1.261[/tex] × [tex]155) / 76.14[/tex]

[tex]= (195.455 / 76.14)[/tex]

[tex]= 2.567[/tex] moles of Carbon Disulfide

Number of moles of Naphthalene:

Number of moles [tex]= 10.60 / 128.2[/tex]

[tex]= 0.083[/tex]

Now,

Total number of moles :

[tex]2.567 + 0.083[/tex]

[tex]= 2.65[/tex] moles

Mole fraction of each compound in solution :

Carbon Disulfide:

2.567 / 2.65

[tex]= 0.969[/tex]

Naphthalene

0.083 / 2.65

[tex]= 0.031[/tex]

According to Raoult's:

P[tex]solution = Xsolvent[/tex] × [tex]Posolvent[/tex]

Carbon Sulfide = Solvent

[tex]Xsolvent =[/tex] Mole fraction of solvent

[tex]Posolvent =[/tex] Vapour  pressure of the pure solvent

[tex]Psolution[/tex] [tex]= 0.969[/tex] × [tex]355.6 torr[/tex]

[tex]= 344.5764[/tex] torr

Thus, "[tex]344.5764[/tex] torr" is the correct answer.

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Answer:

Mass and density is the answer?

Answer:

C Qualitative Analysis.

Explanation:

Answer:

Aye Wassup? Adam Here :D

Explanation:

Nitrogen dioxide is a chemical compound with the formula NO 2.It is one of several nitrogen oxides. NO 2 is an intermediate in the industrial synthesis of nitric acid, millions of tons of which are produced each year for use primarily in the production of fertilizers.At higher temperatures it is a reddish-brown gas.

Hope This Helped Bro: "AdamDaAssasin"

Answer:

The freezing point is -3.72 degrees Celsius

Explanation:

In this question, by assuming the complete dissociation of the salt, we want to calculate the freezing point of an aqueous 1 M NaCl solution .

We proceed as follows;

Firstly, we write the dissociation equation;

NaCl ——> Na+ + Cl-

So the number of ions present in the dissociation is 2. This means that the Vant Hogg factor also called I = 2

Mathematically;

ΔTf = Kf*m*i

m represents the molality which is given as 1

So by substituting the values, we have;

ΔTf = 1.86 * 1 * 2 = 3.72 degrees Celcius

The freezing point however is 0 - ΔTf = 0 - 3.72 = -3.72 degrees Celcius

Answer:

Temperature on beans sprouted

Explanation:

Answer:

55.85 amu

Explanation:

Let A, B, C and D represent the four isotopes of element X.

The following data were obtained from the question:

Isotope A:

Abundance (A%) = 5.845%

Mass of A = 53.93961 amu

Isotope B:

Abundance (B%) = 91.75%

Mass of B = 55.93494 amu

Isotope C:

Abundance (C%) = 2.123%

Mass of C = 56.93539 amu

Isotope D:

Abundance (D%) = 0.2820%

Mass of D = 57.93328 amu

Average atomic mass of element X =.?

The average atomic mass of X can be obtained as follow:

Average Atomic mass = [(Mass of A × A%)/100] + [(Mass of B × B%)/100] + [(Mass of C × C%)/100] + [(Mass of D × D%)/100]

Average Atomic mass = [(53.93961 × 5.845)/100] + [(55.93494 × 91.75)/100] + [(56.93539 × 2.123)/100] + [(57.93328 × 0.2820)/100]

= 3.15277 + 51.32031 + 1.20874 + 0.16337

= 55.84519 ≈ 55.85

Therefore, the average atomic mass of X is 55.85 amu

Answer:

Dobereiner could find only three triads; . i.e total of 9 elements only. However the total number of elements were more than that of those encompassed in Dobereiner's Triad

Explanation:

Answer:

Dobereiner could find only three triads; . i.e total of 9 elements only. However the total number of elements were more than that of those encompassed in Dobereiner's Triad. Thus, Dobereiner's could not be classify most of the elements known at that time

Explanation:

This work is not my own.... copied from google but hope this helps you.

Matter are anything that is made up of atoms. The quantity of matter can be observed only on the basis of mass and volume calculation. Therefore, the correct option is option C.

Matter is a substance that has some mass and can occupy some volume. The matter is mainly used in science. Matter can be solid, liquid or gas.

Matter is anything that is made up of atoms. Anything around us that can be physically seen and touched are matter. Ice, water and water vapors are example of matter.

Cytosol is the liquid medium contained within a cell. The cytosol is a component of the cytoplasm. Out of given option cytosol  has the greatest concentration of potassium ions. The cytoplasm does not include the nucleus.

Therefore, the correct option is option C.

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Answer:

Silicon tetrachloride

Dinitrogen tetroxide

The name of the compound SiCl₄ is named silicon tetrachloride and N₂O₄ is named dinitrogen tetroxide.

SiCl₄ is named silicon tetrachloride. It is composed of one silicon atom (Si) bonded to four chlorine atoms (Cl). The prefix "tetra-" indicates the presence of four chlorine atoms bonded to the central silicon atom.

N₂O₄ is named dinitrogen tetroxide. It consists of two nitrogen atoms (N) bonded to four oxygen atoms (O). The prefix "di-" indicates the presence of two nitrogen atoms, and the suffix "-tetraoxide" indicates the presence of four oxygen atoms.

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Answer: .B. 13C NMR spectra display peaks for only carbons that bear hydrogen atoms.

Explanation:

The statements that are true about 13C NMR are:

A. In 13C proton-decoupled NMR spectra, all peaks are singlets.

C 13C NMR chemical shifts occur over a greater range than 1H NMR chemical shifts.

D. 13C NMR easily differentiates between the different hybridized carbons (sp3, sp2, and sp hybridized carbons).organic-chemistry

Therefore, the option that isn't true is option B. "13C NMR spectra display peaks for only carbons that bear hydrogen atoms". This is false because 13C NMR will show every peak in the spectrum and it doesn't matter if it's only carbons that bear hydrogen atoms as everything will be shown.

Answer:

[tex]Ksp=[Zn^{2+}]^3[PO_4^{3-}]^2[/tex]

Explanation:

Hello,

In this case, since the equilibrium dissociation of zinc phosphate is:

[tex]Zn_3(PO_4)_2(s)\rightleftharpoons 3Zn^{2+}(aq)+2(PO_4)^{3-}(aq)[/tex]

Due to the fact that only the zinc and phosphate ions are in aqueous state, the solubility product expression is written considering the law of mass action in which the concentration of each species is powered to the corresponding stoichiometric coefficient as follows:

[tex]Ksp=[Zn^{2+}]^3[PO_4^{3-}]^2[/tex]

Best regards.

Answer:

Self-reduction is a reaction in which no external reducing agent is required. It is called self-reducing because copper oxide itself reduced the copper sulfide to give copper and sulfur dioxide.

Answer:

experiment showed that the atom is mostly empty space with a tiny, dense, positively-charged nucleus.

Explanation:srry im late but i dont be on it like that  hoped it helped tho srry

In Au₂SO₄, the charge on each gold atom is +3.

The charge on the transition metal gold (Au) in Au₂SO₄ can be determined by considering the overall charge of the compound and the charges of the other ions present. In this case, the sulfate ion carries a charge of -2.

Charge on Au: +3

In Fe₂(CrO₄)₃, the transition metal iron (Fe) is present. The compound contains two iron atoms. To determine the charge on each iron atom, the charges of the other ions in the compound. The chromate ion carries a charge of -2, and the compound as a whole is neutral.

Charge on Fe: +3

The transition metal zinc (Zn) is present in Zn(OH)₂. To determine the charge of the zinc ion, to consider the charges of the other ions. The hydroxide ion (OH-) carries a charge of -1. Since there are two hydroxide ions, their combined charge is -2.

Charge on Zn: +2

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Answer:

72 million because they needed to raise cash for its development

Explanation:

It is a known fact that at lunch Ethereum had only 72 million tokens in existence back in July 2015. In other to develop the Blockchain network further, the founder, Vitalik Buterin organized a fundraising event around July and August 2014.

Fast forward to the year 2020, Ether now has a total supply of about 112 million.

Answer:

To instill a high degree of personal honor, self-reliance, and confidence in each cadet by presenting a military environment in which cadets will be forced to rely upon themselves and their shipmates to study, work, and learn.

-78° Celsius is the temperature in units of degrees Celsius.

Temperature is the measure of hotness or coldness expressed in terms of any of several scales, including Fahrenheit and Celsius.

195 Kelvin = 195 - 273.15 = -78.15 Celsius.

-78° Celsius is the temperature in units of degrees Celsius.

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