Answer:
This is true. A hot glass does look the same as a cold glass. Glass won't change its look if it's below 648 degrees Celsius.
Phosphorous-32 has a half life of 14.3 days while radon-222 has a half-life of 3.8 days, so phosphorous-32 is considered more active.
a. True
b. False
2. An Isotope of technetium, mixed with sulphur and colloidally dispersed in water, is frequentyused in diagnosing various medical conditions because it is readily taken up by various tissues Prior to excretion. Explain why this important
mixture is not a true solution.
Answer:
This is not a true solution because the colloidal dispersion is not completely homogeneous, and it does not have uniform properties throughout.
Explanation:
hope i helped
Axon diameters of cortico-cortical fibres in the human brain range from 0.16 um to 9 um in
length. Convert the length, 0.16 um, into meters using scientific notation. (Use the following
format: a x 10^b using the correct number of significant figures).
Type your answer and submit
1.6x10^-7
Х
Conversion from one unit to another requires the use of a conversion factor.
We are required in the problem to express our result in the form; a x 10^b
To convert from μm to m, the conversion factor to use is [tex]1 * 10^-6[/tex]
So;
1 μm = [tex]1 * 10^-6[/tex] m
0.16 μm = 0.16 μm * [tex]1 * 10^-6[/tex] m/1 μm
= [tex]1.60 * 10^-7[/tex] m
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write the chemical formula of the following compounds sodium sulfate magnesium chloride aluminum nitrate ammonium sulfate
Explanation:
Magnesium chloride = MgCl₂
aluminum nitrate= Al(NO₃)₃
ammonium sulfate=( NH₄)₂SO₄
Convert 355 km/s into m/ns.
Answer:
3.55e-7
Explanation:
specific gravity of a vegetable oil is 0.85. What is its density?
1. Based on the following balanced equation:
2 H2 + O2 + 2H2O
a. How many moles of O2 are required to react completely with 2.00 moles of H2?
1.00 1.50 2.00 2.50 3.00 3.50 4.00 4.50 5.00
b. How many moles of H2O are produced after complete reaction of 2.00 moles of H2?
1.00 1.50
2.00 2.50 3.00 3.50 4.00 4.50 5.00
Answer:
a. 1 mole O2
b. 2 moles H2O
Explanation:
a. 2 moles H2 x [tex]\frac{1 mole O2}{2 moles H2}[/tex] = 1 mole O2
B. 2 moles H2 x [tex]\frac{2 moles H2O}{2 moles H2}[/tex] = 2 moles H20
Question 25 of 30
Several dyes were mixed together and dissolved in water. You need to
determine which dyes are in the solution, but not separate the entire mixture.
How can you separate out a small sample of the dyes for identification
purposes, but not separate the entire mixture?
A. By distilling the dyes
B. By filtering the dyes
C. By using oils to distill the dyes
D. By using chromatography
SUBMIT
We can separate out a small sample of the dyes for identification purposes, but not separate the entire mixture by using chromatography.
What is Chromatography?Chromatography is a technique of separation of mixtures of liquids according to the nature of those liquids.
To get the process started, the mixture is dissolved in a substance called the mobile phase, which carries it through a second substance called the stationary phase.
The different components of the mixture travel through the stationary phase at different speeds, causing them to separate from one another. The nature of the specific mobile and stationary phases determines which substances travel more quickly or slowly, and is how they are separated. These different travel times are termed retention time.
Therefore, We can separate out a small sample of the dyes for identification purposes, but not separate the entire mixture by using chromatography.
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How does the carbonyl group increase the reactivity of carboxylic acids?
Answer:
The relative reactivity of carboxylic acid derivatives toward nucleophile substitutions is related to the electronegative leaving group's ability to activate the carbonyl. The more electronegative leaving groups withdraw electron density from the carbonyl, thereby increasing its electrophilicity.
Hope it helps you.explain what happens in terms of heat diffusion
Answer:
here is the answer
Explanation:
Diffusion is a process of passive transport in which molecules move from an area of higher concentration to one of lower concentration.
Where does water pollution come from
Answer:Water pollution can come from a variety of sources. Pollution can enter water directly, through both legal and illegal discharges from factories, for example, or imperfect water treatment plants. Spills and leaks from oil pipelines or hydraulic fracturing (fracking) operations can degrade water supplies.
Explanation:
7 f Find the volume in dm3 and in mole of 0.505m of NaoH required to react with 40ml of 0.505m
of H₂SO4 Solution
The volume of NaOH required is 0.08 dm³
To solve this question, we'll begin by writing the balanced equation for the reaction between H₂SO₄ and NaOH. This is illustrated below:
H₂SO₄ + 2NaOH —> Na₂SO₄ + 2H₂O
From the balanced equation above,
Mole ratio of the acid, H₂SO₄ [tex](n_{A}) = 1[/tex]
Mole ratio of the base, NaOH [tex](n_{B}) = 2[/tex]
Next, we shall determine the volume of NaOH required to react with H₂SO₄. This can be obtained as follow:
Molarity of the base, NaOH [tex](M_{B}) = 0.505 M[/tex]
Volume of the acid, H₂SO₄ [tex](V_{A}) = 40 mL[/tex]
Molarity of the acid, H₂SO₄ [tex](M_{A}) = 0.505 M[/tex]
Volume of the base, NaOH [tex](V_{B})[/tex] =?[tex]\frac{M_{A} * V_{A}}{M_{B} * V_{B}} = \frac{n_{A}}{n_{B}}\\\\\frac{0.505 * 40}{0.505 *V_{B}} = \frac{1}{2}\\\\\frac{20.2}{0.505 *V_{B}} = \frac{1}{2}[/tex]
Cross multiply
[tex]0.505 * V_{B} = 20.2 * 2\\0.505 * V_{B} = 40.4[/tex]
Divide both side by 0.505
[tex]V_{B} = \frac{40.4}{0.505}\\\\V_{B} = 80 mL[/tex]
Finally, we shall convert 80 mL to dm³. This can be obtained as follow:
[tex]1000 mL = 1 dm^{3}\\\\Therefore,\\\\80 mL = \frac{80 mL * 1dm^{3}}{1000 mL}\\\\80 mL = 0.08dm^{3}[/tex]
Therefore, the volume of NaOH required is 0.08 dm³
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Write a balanced equation for the ionization of hydrochloric acid in water. Assume that hydronium ion is formed. (Use the lowest possible coefficients. Be sure to specify states such as (aq) or (s). If a box is not needed, leave it blank.)
Answer:
HCl(g) + H₂O(l) -> Cl⁻(aq) + H₃O⁺(aq)
Explanation:
Usually when we have HCl in a lab, it's already dissolved in water. It's just HCl(aq). If we want to look at adding pure HCl, that'll be a gas. We should note that HCl is a strong acid that will break apart completely. One might not say that this is a chemical reaction so much as a dissociation. Strong acids are proton donors and form hydronium cations in aqueous solution.
The balanced equation for the ionization of hydrochloric acid (HCl) in water, forming hydronium ions (H₃O⁺) and chloride ions (Cl⁻) is:
HCl(aq) + H₂O(l) → H₃O+(aq) + Cl⁻(aq). The symbol for hydrochloric acid is HCl. H₂O stands for water. The hydronium ion, or H₃O+, is created when the acid HCl gives a proton (H+) to a water molecule.
The chloride ion, which is what's left of the HCl molecule after it's been ionized, is denoted by the symbol Cl-.
The reaction can move both in the forward (ionization) and backward (recombination) directions, according to the double arrow ().
Thus, The balanced equation for the ionization of hydrochloric acid (HCl) in water, forming hydronium ions (H₃O⁺) and chloride ions (Cl⁻).
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A gas cylinder filled with argon is kept at a pressure of 177 atm and 25 degrees C. What is the gas pressure when the temperature of the cylinder and its contents are heated to 195 degrees C by exposure to fire?
Answer:
278 atm
Explanation:
We're gonna use this formula: [tex]\frac{P_1}{T_1} =\frac{P_2}{T_2}[/tex]
P₁ = 177 atm
T₁ = 298 (Convert Celsius to kelvins by adding 273)
P₂ = ?
T₂ = 468 (195 + 273)
We got
[tex]\frac{177}{298} =\frac{P_2}{468}[/tex]
We can cross-multiply or multiply both sides by 468
I'm gonna go with the latter
[tex](468)\frac{177}{298} =\frac{P_2}{468}(468)[/tex]
[tex]P_2 = \frac{(468)(177)}{298}[/tex]
[tex]P_2 = 277.973[/tex]
Answer:
[tex]\boxed {\boxed {\sf 278 \ atm}}[/tex]
Explanation:
We are asked to find the gas pressure when the temperature of a gas is changed. We will use Gay-Lussac's Law, which states the pressure of a gas is proportional to the temperature of the gas. The formula for this law is:
[tex]\frac{P_1}{T_1}=\frac{P_2}{T_2}[/tex]
Initially, the pressure is 177 atmospheres and the temperature is 25 degrees Celsius or 298 Kelvin.
[tex]\frac {177 \ atm}{298 \ K}=\frac{P_2}{T_2}[/tex]
Then, the gas cylinder is exposed to fire and the temperature is raised to 195 degrees Celsius or 468 Kelvin, but the pressure is unknown.
[tex]\frac {177 \ atm}{298 \ K }=\frac{P_2}{468 \ K}[/tex]
We are solving for the new pressure, so we must isolate the variable P₂. It is being divided by 468 Kelvin. The inverse operation of division is multiplication, so we multiply both sides of the equation by 468 Kelvin.
[tex]468 \ K *\frac {177 \ atm}{298 \ K}=\frac{P_2}{468 \ K}*468 \ K[/tex]
[tex]468 \ K *\frac {177 \ atm}{298 \ K}=P_2[/tex]
The units of Kelvin cancel.
[tex]468 \ K *\frac {177 \ atm}{298 \ K }=P_2[/tex]
[tex]468 * 0.593959731544 \ atm = P_2[/tex]
[tex]277.973154362 \ atm = P_2[/tex]
The pressure in the cylinder after exposure to fire is approximately 278 atmospheres.
The products of the hydrolysis of cyclohexene
Answer:
CH3
Explanation:
Answer:
cyclohexene
One molecule of cyclohexanol should produce one molecule of cyclohexene. One mole (mol) of cyclohexanol should produce one mole of cyclohexene.
Explanation:
The major products of the complete hydrolysis of disaccharides and polysaccharides are three monosaccharide units: glucose, fructose, and galactose.
Shakespeare's A Midsummer Night's
Dream contains dialogue that is
meant to be performed. In what
narrative genre does this story fit?
A. historical fiction
B. mystery
C. play
Why is the half-life of a radioisotope important for radioactive dating?
A. The half-life forms a type of clock used to calculate time passed.
B. The half-life of a radioisotope tells how long ago the element was
formed.
C. The age of an object is equal to the radioisotope with the longest
half-life in it.
D. The half-life gives the period over which the radioisotope doesn't
change.
Answer:Dating Using Radioactive Decay
The best-known techniques for radioactive dating are radiocarbon dating, potassium-argon dating and uranium-lead dating.
After one half-life has elapsed, one half of the atoms of the nuclide in question will have decayed into a “daughter” nuclide.
Explanation:d
calculate the number of moles in 2.5 particle NaOH
Answer:
1.5055×10²⁴
Explanation:
................................
Please help thank you (20 points)
Answer:
Answer is b gravity only
describe five factors which affect propagation of sound.. please describe in details.
Answer:
Explanation:
Image result for describe five factors which affect propagation of sound.. please describe in details.
There are several important factors which affect the propagation of sound: geometric spreading, atmospheric effects, and surface effects. These are discussed separately below. This refers to the spreading of sound energy as a result of the expansion of the wavefronts.
Hydrochloric acid is used to produce fertilizers and dyes, to pickle and clean metal products, and as a reagent in the photographic and rubber industries. Which of the following is a chemical property of hydrochloric acid?
Liquid hydrochloric acid can vaporize into a gas at 48 degrees Celsius
All of these are chemical properties of hydrochloric acid
Hydrochloric acid is soluble in water
Hydrochloric acid reacts with the materials to produce bubbling, or fizzing, a gas, and heat.
Answer:
Hydrochloric acid reacts with the materials to produce bubbling, or fizzing, a gas, and heat.
Explanation:
sheilding effect definition please
Answer:
give me brainliest
Explanation:
The shielding effect sometimes referred to as atomic shielding or electron shielding describes the attraction between an electron and the nucleus in any atom with more than one electron. The shielding effect sometimes referred to as atomic shielding or electron shielding describes the attraction between an electron and the nucleus in any atom with more than one electron.
Answer:
The shielding effect can be defined as a reduction in the effective nuclear charge on the electron cloud
Explanation:
i am not sure but i hope it will help you
If squares represent carbon and spheres represent chlorine make a representation of liquid CCl4
Answer:
Look in explanation
Explanation:
I have shown the Lewis diagram as well as the square and sphere representation.
At constant temperature, the volume of the container that a sample of nitrogen gas is in is doubled. As a result, the pressure of the nitrogen gas is halved. The amount of nitrogen gas is unchanged in this process. This is an example of:
Boyles law!! Pressure is inversely proportional to volume!
Que sucede cuando a una molécula sencilla se le sustituye un hidrógeno por un grupo oh
Answer: What happens when a single molecule is replaced by a hydrogen by an oh group
Explanation:
a cyclist starts at rest and accelerates at 4m/s^2 south for 30s what is the cyclist final velocity?
Answer:
120
Explanation:
6. During the titration, splatter from the drops of NaOH splashed some of the KHP solution onto the sides of the Erlenmeyer flask. If the student did not rinse these droplets back down into the solution with distilled water, how would that have affected the calculation of concentration of NaOH
Answer:
A titration is an analytical procedure used to determine the concentration of a sample by reacting it with
a standard solution. One type of titration uses a neutralization reaction, in which an acid and a base
react to produce a salt and water.
In a titration, the standard solution goes in a buret, which is a piece of glassware used to measure the
volume of solvent to approximately 0.1 mL of accuracy. The solution that you are titrating goes in an
Erlenmeyer flask, which should be large enough to accommodate both your sample and the standard
solution you are adding.
Determine the percent water in CuSO4∙5H2O to three significant figures
Answer: 36.1%
Explanation: The molar mass of the complete molecule, CuSO4*5H2O is 249.6 g/mole. The molar mass of just the water (5H20) is 90 g/mole. Assume 1 mole of CuSO4*5H2O, the percent water would be:
90g H2O/249.6g CuSO4*5H2O = 0.361 or 36.1%
9.
Unless specifically instructed to do so, what should you never put into a flame?
Answer:
Gas
Explanation:
Do not put any sub- stance into the flame unless specifically instructed to do so. Never reach over an exposed flame. Light gas (or alcohol) burners only as instructed by the teacher.
Is the covalent bond BH2CL a polar nonpolar or ionic compound
BH2Cl is a polar compound because the molecule is non-symmetrical.
An ionic bond is usually formed between atoms having a high magnitude of electronegativity difference between them while covalent molecules tend to have a narrower range of electronegativity difference between atoms in the molecule.
In-between the two extremes are the polar covalent bonds which result from a significant electronegativity difference but less than that required for an ionic bond.
The B-Cl bond in BH2Cl is polar and the entire molecule is non-symmetrical hence the BH2Cl is a polar compound.
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