Answer:
Different objects appear to be different colors, because we see color by light bouncing off an object and reflecting or transmitting into our eye. The amount of light that reflects or transmits into our eye depend on the color that we will see.
Which of the following is the Arrhenius equation?
Answer:
A is the answer the reason why is because I got it right when I was doing my test
You have three BSA working solutions: 5ug/ul, 0.5 ug/ul, and 0.05 ug/ul. Each tube contains 500 ul of solution. How much of which concentration(s) would you pipet into three different centrifuge tubes so you end up with 20 ug, 2 ug, and 0.2 ug of BSA in each tube
Answer:
I would pipet 4 μl of each BSA work solution
Explanation:
To calculate the mass (in μg), we have to multiply the concentration C (in μg/ul) by the volume V (in μl):
C(μg/ul) x V( μl) = mass (μg)
We found the required volume for each solution, as follows:
5 μg/μl x V₁ = 20 μg ⇒ V₁ = 20 μg/(5 μg/μl ) = 4 μl
0.5 μg/μl x V₂ = 2 μg ⇒ V₂ = 2 μg/(0.5 μg/μl) = 4 μl
0.05 μg/μl x V₃ = 0.2 μg ⇒ V₃= 0.2 μg/(0.05 μg/μl) = 4 μl
Therefore, we need to pipet 4 μl of the solutions of concentrations 5μg/μl, 0.5 μg/μl, and 0.05 μg/μl to obtain the masses 20 μg, 2 μg, and 0.2 μg, respectively.
A radioactive substance has a half-life of 5 million years. What is the age of a rock in which 25% of the original radioactive atoms remain
Answer:
d. 10 million years
Explanation:
These are the options for the question
Choose one answer.
a. 2.5 million years
b. 5 million years
c. 15 million years
d. 10 million years
✓half-life of the radioactive substance= 5 million years
✓ Then for every 5 million years, original radioactive given (100%) percentage is reduced by factor of 1/2.
✓ 1st 5 million year; After the first 5 million years, the original radioactive is reduced as;
(100%) × 1/2 = 50% remains
✓2nd 5 million year: At 10 millions year, the 50% remaining radioactive is reduced by factor of 1/2
(50%) × 1/2 = 25% remains
Hence, at At 10 millions years 25% of the original radioactive atoms remain
.
Answer:
10 million years
Calculate the molarity (M) if 3.35g of H3PO4 is dissolved in water to give a total volume of 200mL
Answer:
0.171 M
Explanation:
Step 1: Given data
Mass of H₃PO₄ (solute): 3.35 gVolume of solution (V): 200 mLStep 2: Calculate the moles of solute
The molar mass of H₃PO₄ is 97.99 g/mol.
3.35 g × 1 mol/97.99 g = 0.0342 mol
Step 3: Convert "V" to liters
We will use the conversion factor 1 L = 1000 mL.
200 mL × 1 L/1000 mL = 0.200 L
Step 4: Calculate the molarity of the solution
We will use the definition of molarity.
M = moles of solute / liters of solution
M = 0.0342 mol/0.200 L = 0.171 M
A change of state is a(n)
process.
A. irreversible
B. reversible
Answer:
Changes of states are reversible, you can go from a solid to liquid and liquid to solid.Answer:
Reversible
Explanation:
Changes of state are physical changes in matter. Common changes of the state include melting, freezing, sublimation, deposition, condensation, and vaporization.
which would be a stronger acid H3PO4 or H3PO2
Answer:
h3po2
Explanation:
Answer:
i think it is H3PO4
Explanation:
A 32.60 g sample of a solid is placed in a flask. Toluene, in which the solid is insoluble, is added to the flask so that the total volume of solid and liquid together is 51.00 mL . The solid and toluene together weigh 58.86 g . The density of toluene at the temperature of the experiment is 0.864 g/mL. What is the density of the solid?
Answer:
0.864 g/mL.
Explanation:
I hope this helps u! also have a great rest of your day!
The number of atoms in 10. grams of calcium is equal to 6.0 x 1023 multiplied by which number?
Answer:
1.51×10²³ atoms.
Explanation:
From the question given above, the following data were obtained:
Mass of Calcium (Ca = 10 g
Number of atom of Calcium (Ca) =?
The number of atoms present in 10 g of Ca be obtained as follow:
From Avogadro's hypothesis, we understood that 1 mole of any substance contains 6.02×10²³ atoms. This implies that 1 mole Ca contains 6.02×10²³ atoms.
1 mole of Ca = 40 g.
Now, if 40 g of Ca contains 6.02×10²³ atoms.
Therefore, 10 g of Ca will contain = (10 × 6.02×10²³) / 40 = 1.51×10²³ atoms.
Thus, 10 g of calcium contains 1.51×10²³ atoms.
first answer will get brainliest
Answer:
Incorrect
Explanation:
Mole ratios are derived from the coefficients in front of the number, N2O does not have a 2 in front of it, the real mole ratio would be 4/1
Answer:
Correct
Explanation:
I had the same problem and I put correct, and it was correct.
Using your own words whats the difference between weather and climate
Answer:
Weather is at a specific place and time. Climate is over a period of time.
Explanation:
That is the difference
Who has the more valued Exports?
South Africa or Egypt?
pls help ill mark brainliest! star and heart :)
Answer:
Egypt
Explanation:
Hi again
Part I: SP3 Hybridization: B: Ethane Distance between C-C in ethane: ________________ Distance between H atoms in eclipsed conformation: ________________ Distance between H atoms in staggered conformation: ________________ Which is more stable (circle one): STAGGERED or ECLIPSED
Answer:
Distance between C-C in ethane- 1.54 Å
Distance between H atoms in eclipsed conformation-2.3 Å
Distance between H atoms in staggered conformation- 2.5 Å
Staggered conformation is more stable
Explanation:
The staggered conformation of ethane can be demonstrated as the most stable of conformation of ethane, because the angles between Carbon-Hydrogen bonds in both the front and back carbon atoms are maximized. This now minimizes the energy of this conformation compared to the eclipsed conformation.
Considering the eclipsed conformation, it is obvious that the electron densities on Carbon-Hydrogen bonds come very close together thereby bringing two C-H bonds into a dihedral angle of almost zero degrees. This causes their electron clouds to experience strong repulsion, thereby raising the molecules's total energy.
When Elsa freezes things, is it an example of an exothermic or
endothermic reaction? Explain.
Answer:
endothermic reaction
Explanation:
When Elsa from Frozen freezes things, it is an example of an endothermic chemical reaction.
An endothermic involves a reaction in which heat is absorbed from the surrounding. Hence the surrounding becomes colder at the end of the the change.
So, Elsa draws heat from the environment and this causes the environment to be colder and things that are in contact with her.
In order to produce some SbCl5, a 1.00 mole sample of SbCl3 is first placed in an empty 2.00 liter container maintained at a temperature different from 182oC. At this temperature, Kc, equals 0.117. How many moles of Cl2 must be added to this container to reduce the number of moles of SbCl3 to 0.700 mole at equilibrium
x = = 0.50 M Answer:
In order to produce some SbCl5, a 1.00 mole sample of SbCl3 is first placed in an empty 2.00 liter container maintained at a temperature different from 182oC. At this temperature, Kc, equals 0.117. How many moles of Cl2 must be added to this container to reduce the number of moles of SbCl3 to 0.700 mole at equilibrium
Moles Cl2 that must be added = 0.40 mol
Explanation:
K = ( = 0.117
Equilibrium concentrations:
= (1.00 - 0.70) mol / 2.00 L = 0.15 M <<---why is it 1.00-0.70???
= 0.700 mole / 2.00L = 0.350 M
= x
Kc = ÷ (0.15) = 0.117
Moles Cl2 at equilibrium = 0.050 mol L x 2.00 L = 0.10 mol
Moles Cl2 needed to make 0.300 mol SbCl3 into SbCl5 = 0.30 mol
Moles Cl2 that must be added = 0.40 mol
0
Which is not one of Earth's layers?
A А
crust
B)
inner core
mantle
D
ocean
The ocean is not a part of Earth's layers.
Answer:
Ocean
Explanation:
A student performs an experiment to determine the molar mass of magnesium oxide. The student repeats the experiment five times and collects the following data: 40.220gmol, 40.654gmol, 40.314 gmol, 40.165 gmol, and 40.554 gmol. If the accepted value for the molar mass is 40.304 gmol, what is the percent relative error for the average of this data?
Answer:
Percent relative error = 0.191%
Explanation:
Relative error is a measure of accuracy (How closeness is the measure to the accepted value) for a determined data. The formula is:
Percent relative error = |Experimental - Accepted| / Accepted * 100
Where experimental is the average of the data:
(40.220g/mol + 40.654g/mol + 40.314g/mol + 40.165g/mol + 40.554g/mol) / 5 =
40.381g/mol
Replacing using accepted value = 40.304g/mol:
|40.381g/mol - 40.304g/mol| / 40.304g/mol * 100
Percent relative error = 0.191%there is concern in health-related government agencies that the american diet contains too much meat, and numerous recommendations have been made urging people to consume more fruit and vegetables. one of the richest sources of vegetable protein is soy, available in many forms. among these is soybean curd, or tofu, which is a staple of many asian diets. chemists have isolated an anticancer agent called genistein from tofu, which may explain the much lower incidence of cancer among people in the far east. a valid lewis structure for genistein is
Answer:
Explanation:
The aim of this question is to draw the structure of genistein and determine the number of atoms with sp² hybridization in the molecule.
From the image below, we will see the lewis structure of genistein. From the image, the blue asterisk atoms are sp² hybridized and the red marked atoms are sp³ hybridized.
We will also notice that all the carbon atoms contain 3 σ-bonds with no lone pair of electrons.
Using the knowledge of Valence shell electron repulsion theory (VSEPR), the above-mentioned carbon atom is said to be sp²hybridized.
Also, the oxygen atoms which are doubly bounded contains 1 σ-bond and 2 lone pair electrons. These oxygen atoms are also sp² hybridized.
Finally, the singly bonded oxygen atom is composed of 2 σ-bonds and 2 lone pair electrons. This makes it to be sp³ hybridized.
Altogether, we have a total of 16 sp² hybridized atoms and 4 sp³ hybridized atoms.
After a recrystallization, a pure substance will ideally appear as a network of __________. If this is not the case, it may be worthwhile to reheat the flask and allow the contents to cool more _________
Answer:
Large crystals
Slowly
Explanation:
Recrystallization is a procedure used to purify an impure compound in a solvent. The concept used here is that the solubility of most of the solids increases with increase in temperature.
Recrystallization is also called as method of fractional crystallization.
After a recrystallization, a pure substance will ideally appear as a network of large crystals. If this is not the case, it may be worthwhile to reheat the flask and allow the contents to cool more slowly.
Which of the following has the largest atomic radius?
Answer:
b
Explanation:
S2- has the same electron configuration as which neutral element?
Answer:
ANSWER OS HERE
Explanation:
THE O2- has two more extra electrons due to presence of 2 negative charges so a total of 10 electrons and the element that has 10 electrons in the periodic table in its neutral state is Neon (Ne) ( atomic number (10) = no.of protons = no. of electrons) so neutral element with same electron configuration as O2- is Ne. Log in or register to post comments.
The electron configuration of the neutral atom is an useful place to start when trying to determine the electron configuration of an ion.
What is the idea behind this?The neutral atom in your situation is sulfur (S), which is found in group 16 of period 3 of the periodic chart. A neutral sulfur atom has a total of 16 electrons surrounding its nucleus since sulfur has an atomic number of 16. Thus, a neutral sulfur atom will have the following electron configuration. Now, a neutral sulfur atom receives two more electrons to create the sulfide anion, or S2. These two electrons will be added to the 3p-orbitals, which can hold a maximum of two protons, as you can see in the configuration of the neutral atom. between them, a maximum of six electrons. Thus, the sulfide anion's electron configuration will be the electron configuration of neon, the noble gas that appears before sulfur in the periodic table, will be used in the shorthand notation for noble gases for the sulfide anion.
To know more about Electronic configuration, visit-https://brainly.com/question/13497372
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Balance the equation
Answer:2NaF + Br2 —> 2NaBr + F2
2K + Cl2 —> 2KCl
N2+ 3F2 —> 2NF3
Explanation:
16. Using the average atomic masses given in the inside front cover of this book, calculate the indicated quantities.
d. the number of moles of cobalt represented by 5.99 x 1021 cobalt atoms e. the mass of 4.23 mol of cobalt
f. the number of cobalt atoms in 4.23 mol of cobalt
g. the number of cobalt atoms in 4.23 g of cobalt
Answer:
d. 9.95 × 10⁻³ mol
e. 249 g
f. 2.55 × 10²⁴ atoms
g. 4.32 × 10²² atoms
Explanation:
d. the number of moles of cobalt represented by 5.99 x 10²¹ cobalt atoms
We will use Avogadro's number: there are 6.02 × 10²³ atoms of cobalt in 1 mole of atoms of cobalt.
5.99 x 10²¹ atoms × 1 mol/6.02 × 10²³ atoms = 9.95 × 10⁻³ mol
e. the mass of 4.23 mol of cobalt
The molar mass of cobalt is 58.93 g/mol.
4.23 mol × 58.93 g/mol = 249 g
f. the number of cobalt atoms in 4.23 mol of cobalt
We will use Avogadro's number: there are 6.02 × 10²³ atoms of cobalt in 1 mole of atoms of cobalt.
4.23 mol × 6.02 × 10²³ atoms/1 mol = 2.55 × 10²⁴ atoms
g. the number of cobalt atoms in 4.23 g of cobalt
First, we will calculate the moles of cobalt using the molar mass of cobalt.
4.23 g × 1 mol/58.93 g = 0.0718 mol
Then, we will calculate the number of cobalt atoms using Avogadro's number.
0.0718 mol × 6.02 × 10²³ atoms/1 mol = 4.32 × 10²² atoms
3. The doctor notices that Janet has long fingernails, and comments that fingernails grow at a rate (or
speed) of 2.50 cm / year. Convert this speed to kilometers / second. Show your work. (6 pts)
Answer:
7.93 × 10⁻¹³ km/s
Explanation:
Step 1: Given data
Rate of growth of the fingernails (r): 2.50 cm/year
Step 2: Convert "r" from cm/year to km/year
We will use the following conversion factors.
1 m = 100 cm1 km = 1000 m[tex]\frac{2.50cm}{year} \times \frac{1m}{100cm} \times \frac{1km}{1000m} = 2.50 \times 10^{-5} km/year[/tex]
Step 3: Convert "r" from km/year to km/s
We will use the following conversion factors.
1 year = 365 day1 day = 24 h1 h = 60 min1 min = 60 s[tex]\frac{2.50 \times 10^{-5} km}{year} \times \frac{1year}{365day} \times \frac{1day}{24h} \times \frac{1h}{60min} \times \frac{1min}{60s} = 7.93 \times 10^{-13} km/s[/tex]
2.50 cm/year is equal to 7.93 × 10⁻¹³ kilometers/second.
What is an ecosystem? ?
Answer:
An ecosystem is a community or group of living organisms that live in and interact with each other in a specific environment.
Explanation:
That's the most straight forward explanation I could come up with
Which element is classified as a transition metal?
A) lithium (Li)
B) zirconium (Zr)
C) tellurium (Te)
D) xenon (Xe)
Answer:
C) tellurium (Te) is the correct answer.
Select the correct coefficients to balance the reaction given below.
__Al + ___O₂ → ____ Al₂ O₃
Answer:
4Al+3O2→2Al2O3
Explanation:
PLZ HELP ASAP WILL
GIVE BRAINLISTS TO RIGHT ANSWER
2KCIO3 → 2KCI + 302
How many grams of potassium chloride are produced if 52 g of potassium chlorate decompose?
A )32 g KCI
B )19 g KCI
C)44 g KCI
D)1.5 g KCI
Answer:
A) Mass = 32 g of KCl
Explanation:
Given data:
Mass of potassium chloride produced = ?
Mass of potassium chlorate = 52 g
Solution:
Chemical equation:
2KClO₃ → 2KCl + 3O₂
Number of moles of KClO₃:
Number of moles = mass/molar mass
Number of moles = 52 g/ 122.55 g/mol
Number of moles = 0.424 mol
Now we will compare the moles of KClO₃ and KCl
KClO₃ : KCl
2 : 2
0.424 : 0.424
Mass of KCl:
Mass = number of moles × molar mass
Mass = 0.424 mol × 74.55 g/mol
Mass = 32 g
us
If the mole fraction of NaCl in an
aqueous solution is 0.0927, what is
the weight/weight % (percent by
mass) of NaCl.
Molar Mass
Naci: 58.44 g/mol
H2O: 18.016 g/mol
Answer:
24.9%
Explanation:
According to this question, mole fraction of NaCl in an aqueous solution is 0.0927. This means that the mole percent of NaCl in the solution is:
0.0927 × 100 = 9.27%
Let's assume that the solution contains water (solvent) + NaCl (solute), hence, the mole fraction of water will be;
100% - 9.27% = 90.73%
THEREFORE, it can be said that, NaCl contains 0.0927moles while H2O contains 9.073moles
N.B: mole = mass/molar mass
Given the Molar Mass
NaCl: 58.44 g/mol
H2O: 18.016 g/mol
For NaCl;
0.0927 = mass/58.44
mass = 0.0927 × 58.44
5.42g
For H2O;
9.073 = mass/18.016
mass = 9.073 × 18.016
= 16.35g
Total mass of solution = 16.35g + 5.42g = 21.77g
Mass percent of NaCl = mass of NaCl/total mass × 100
% mass of NaCl = 5.42g/21.77g × 100
= 0.249 × 100
= 24.9%
Answer:
24.9
Explanation:
The concentration of lithium chlorite solution is 12.0% by mass. In a ___g sample of this solution, there are 238.5g of dissolved lithium chlorate.
Answer is A) 1990 but I do not know to go to there please help!
Mass of sample : 1987.5 g≈1990 g
Further explanationGiven
12% mass of Lithium chlorate
Required
Mass of sample
Solution
%mass = (mass of solute/mass of solution) x 100%
mass of solute = mass of Lithium chlorate = 238.5 g
Input the value :
12/100(0.12) = 238.5 g : mass of solution
mass of solution =238.5 : 0.12
mass of solution = 1987.5≈1990 g
why do we need nucleic acid in our cells?
Explanation:
Nucleic acids are the most important macromolecules for the continuity of life. They carry the genetic blueprint of a cell and carry instructions for the functioning of the cell.