Answer:
A and E
Explanation:
Observing means looking or watching with the eyes etc..
Observation is the component of research and involves inspection of the hypothesis. Dissolving table salt and reading a digital scale is an example of observation. Thus, options A and E are correct.
What is an observation?Observation is that the component of the experimental style that defines observance or the review of the activity that underwent sure conditions.
It will be seen as a press release supported hearing, vision, etc. The dissolving of the flavorer is associate degree noticeable task wherever one will see the salt gets dissolved within the water to create a combination.
Similarly, the digital scales are used to measure the substances and use a readouts to estimate the quantity of the reagents to be used by directly seeing on the digital screen of the machine.
Therefore, dissolving salt and digital scale is observable.Hence options A and E are correct.
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The temperature at which carbon dioxide sublimes is about 195 K. What is this
temperature in units of degrees Celsius?
-78° Celsius is the temperature in units of degrees Celsius.
What is temperature?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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Which process results in two identical cells?
O meiosis
O replication
O fertilization
O mitosis
May u please help i mark brainlist ! :D
Answer:
fertilization i think
Explanation:
because during fertilization process two identicle cell divisions takes place
Answer:
fertilization
Explanation:
edgenuity
19) What did Rutherford's experiment show?
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
What is the solubility product expression for Zn3(PO4)2?
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.
The vapor pressure of carbon disulfide is 355.6 torr at 25°C. What is the vapor pressure of a solution prepared by dissolving 10.60 g naphthalene (C10H8, Molar Mass = 128.2 g/mol) in 155 mL CS2 liquid (Molar Mass = 76.14 g/mol, density = 1.261 g/mL)? Assume the solution obeys Raoult's law, and treat naphthalene as a nonvolatile solute.
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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What does a cell nucleus do?
Select one:
a. control everything the cell does
b. surround the cell
c. hold important chemicals the cell needs
d. protect the cell.
Answer:
a. control everything the cell does
Explanation:
the nucleus is like the brain of the cell
A beaker can hold 200 cm3 of water. When it's empty, how
many liters are needed to refill it?
L
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.
Atoms of the same element can have different forms; for example, carbon-12 and carbon-14.
What causes the different forms?
What are these forms called?
Define self reduction reaction.
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.
When measuring solid NaOH in pellet form, explain why you won’t be able to measure exactly 1.000 grams. What are the consequences of this?
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 .
Give the charge on the transition metal of each of the following compounds:
A. Au2SO4
B. Fe2(CrO4)3
C. Zn(OH)2
Enter your answer as +1, +2, etc.
Au
type your answer...
Fe
type your answer...
Zn
type your answer...
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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The uncertainty in the measurement 0.0035 mg is:_______ A) + 0.1 mg B) + 0.01 mg C) 0.001 mg D) + 0.0001 mg
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
How many Ethers were in existence at launch and why? 1. 21 million because they wanted to have more units than Bitcoin 2. 72 million because they couldn't make any less 3. 72 million because they needed to raise cash for its development 4. 21 million because they needed some to use on the testnet
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.
is there any compound like O2C NO2
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"
Which is an example of pure chemistry? a. shape of a soybean plant b. chemicals containing carbon c. finding an antidote
How many neutrons are there in 8 molecules of
[tex] \frac{19}{9} f2[/tex]
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
Significant figure of 0.06300
Answer:
Number of Significant figures is : 4
Scientific Notation is: 6.3 x 10^-2
EXTRA HELP
2-An analysis that establishes the chemical identity of the species
A)Quantitative Analysis
B) Quantitative Synthesis
C)Qualitative Analysis
D)Qualitative Synthesis
Q1-(30 Marks) Choose the correct answer
Answer:
C Qualitative Analysis.
Explanation:
A certain element XX has four isotopes. 5.845% of XX has a mass of 53.93961 amuamu. 91.75% of XX has a mass of 55.93494 amuamu. 2.123% of XX has a mass of 56.93539 amuamu. 0.2820% of XX has a mass of 57.93328 amuamu. What is the average atomic mass of element XX? Express your answer numerically to four signif
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
what were the limitations of Dobereiner's classifcation?
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.
Please help need ASAP!!! Due tonight,
Name the Compounds. Spelling counts
SiCl4
N2O4
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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3. Diesel fuel has a density of 0.839g/mL What is the volume, in gallons, of 2.3 kg of diesel? [1 gallon = 3.79 L)
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:
What is the freezing point of an aqueous 1.00 m NaCl solution? (Kf = 1.86 *C/m) (Assume complete dissociation of the salt.)
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
If you were running an experiment to determine the temperature at which beans sprouted (germinated) the fastest, what would be the outcome (dependent variable)?
Answer:
Temperature on beans sprouted
Explanation:
The variable amount is the amount that changes continuously. We calculate the sprout of the bean at which temperature it is sprouting rapid, in that case, the temperature acts as a variable amount.Which of the following statements about 13C NMR is not true?A. In 13C proton-decoupled NMR spectra, all peaks are singlets.B. 13C NMR spectra display peaks for only carbons that bear hydrogen atoms.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
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.
An example of an extensive physical property is
Group of answer choices
mass
density
boiling point
melting point
Answer:
Mass and density is the answer?
Which of the following fluids has the greatest concentration of potassium ions?
a. Extracellular fluid (ECF).
b. Interstitial fluid.
c. Cytosol.
d. Plasma.
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.
What is matter?
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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help me please, i appreciate it
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.
What is the answer? Please
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.
To what volume (in mL) would you need to dilute 25.0mL of a 1.45 m solution of Kcl to make a 0.0245m solution of KCl
Answer:
The answer is
1479.60 mLExplanation:
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
1479.60 mLHope this helps you