Answer:
true
Explanation:
i need help ):
soo.. help me ! please (:
Answer:
23 Sandwiches
6 slices of bread
0 slices of cheese
Explanation:
brainliest pls:)
Please help I beg you
Answer:
is highly respect is correct I promise!
Suppose that you are a scientist who studies climate changes. While examining the rings of tree trunks, you notice several very large tree rings. What can you conclude about the climate during those years?
Answer:
The climate was wet and cold
Explanation:
Answer:
The large tree rings allow you to conclude that the climate was either very warm or wet during those growing seasons, because greater than normal growth occurred.
Explanation: It is the edge sample response
In an aqueous solution, a 0.100 M solution of glucose is prepared with a total volume of 0.150 Liters. If the molar mass of glucose is 180.16 g/mol how many grams must the solution contain?
Answer:
2.70 g of glucose.
Explanation:
The following data were obtained from the question:
Molarity of the glucose solution = 0.1 M
Volume of solution = 0.15 L
Molar mass of glucose = 180.16 g/mol
Mass of glucose =.?
Next, we shall determine the number of mole of glucose in the solution. This can be obtained as follow:
Molarity of the glucose solution = 0.1 M
Volume of solution = 0.15 L
Mole glucose =?
Molarity = mole /Volume
0.1 = Mole of glucose /0.15
Cross multiply
Mole of glucose = 0.1 × 0.15
Mole of glucose = 0.015 mole
Finally, we shall determine the mass of glucose in the solution as follow:
Mole of glucose = 0.015 mole
Molar mass of glucose = 180.16 g/mol
Mass of glucose =.?
Mole = mass /molar mass
0.015 = mass of glucose /180.16
Cross multiply
Mass of glucose = 0.015 × 180.16
Mass of glucose = 2.70 g
Therefore, the solution contains 2.70 g of glucose.
The grams that the solution must contain is :
- 2.70 g of glucose.
Mole ConceptGiven:
Molarity of the glucose solution = 0.1 M
Volume of solution = 0.15 L
Molar mass of glucose = 180.16 g/mole
Molarity of the glucose solution = 0.1 M
Volume of solution = 0.15 L
Molarity = mole /Volume
0.1 = Mole of glucose /0.15
Mole of glucose = 0.1 × 0.15
Mole of glucose = 0.015 mole
Mole of glucose = 0.015 mole
Molar mass of glucose = 180.16 g/mol
Mass of glucose =.?
Mole = mass /molar mass
0.015 = mass of glucose /180.16
Mass of glucose = 0.015 × 180.16
Mass of glucose = 2.70 g
The solution contains 2.70 g of glucose.
Learn more about "Mole":
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Calculate the percent composition by mass of each element in Al(OH)3.Al(OH)3. Use at least three significant figures.
Answer:
Explanation:
Al(OH)₃
Total molecular weight = 27 + 3 x ( 16+1)
= 78
Al = 27
% of Al = 27 x 100 / 78 = 34.61%
O = 48
% of O = 48 x 100 / 78 = 61.55 %
H = 3
% of H = 3 x 100 / 78
= 3.84%
Al = 34.61%.
O = 61.55%.
H = 3.84%.
Please help. Will give brainliest.
Answer:
B.
Explanation:
i think its B
Which problem that the most scientists believe is partly caused by carbon dioxide?
Answer:
Climate change
Explanation:
Climate change is primarily a problem of too much carbon dioxide (CO2) in the atmosphere. This carbon overload is caused mainly when we burn fossil fuels like coal, oil and gas or cut down and burn forests
What is the pH value of distilled water?
Answer:
7
Explanation:
Consider the following equilibrium.
NH3(aq) + H2O(l) equilibrium reaction arrow NH4+(aq) + OH −(aq)
What will happen to the equilibrium constant if the concentration of OH − increases through the addition of a small amount of NaOH(aq)?
Answer:
It will remain the same
Explanation:
The equilibrium constant of the reaction will remain the same if the concentration of the OH is increased.
Changes in concentration values of any of the reactant does not affect the value of the equilibrium constant.
The equilibrium constant is a constant at a given temperature. It is temperature dependent. Since we have no change in temperature, therefore, the equilibrium constant will not change.The equilibrium constant if the concentration of OH − increases through the addition of a small amount of NaOH(aq) is :
- Remains same.
Equilibrium ReactionThe equilibrium constant of the response will stay the same in case the concentration of the OH is increased.
Changes in concentration values of any of the reactant does not influence the esteem of the equilibrium constant.
The equilibrium constant may be a consistent at a given temperature.
It is temperature dependent. Since we have no alter in temperature.Learn more about "Equilibrium":
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Europium orbital diagram
pls help!!
The number that represents a neutral pH is ________.
Answer:
7
Explanation:
8. Which object has molecules that are moving? water in a cup that is not moving, or water in the ocean
PLEASE HELP ASAP!!!
Answer:
Water in the ocean
Explanation:
The water in the ocean is always moving so all the molecules are was well
The half life of radium-226 is 1600 years.
a. After how many half-lives would 25% of the radium-226 remain.
b. Write a function m(t) that models the mass remaining after years.
c. How much of the sample will remain after 3000 years?
d. After how long will only 15 mg of the sample remain?
Answer:
Explanation:
a )
half life = 1600 years
50% in 1600 years
25% in next 1600 years
so 25% in total of 3200 years .
b )
disintegration constant = .693 / half life
= .693 / 1600
λ= 4.33 x 10⁻⁴ year⁻¹
m(t) = [tex]m_0e^{-\lambda t }[/tex]
m₀ is initial mass , λ = 4.33 x 10⁻⁴ year⁻¹
c )
m(t) after 3000 years , t = 3000
m(t) = [tex]m_0e^{-4.33\times10^{-4 }\times 3000 }[/tex]
= [tex]m_0e^{-1.3}[/tex]
= .2725 m₀
percentage of mass remaining = 27.25 %
25% radium-226 remain after 3200 years. 6.82 mg of sample remains after 3000 years. 15 mg of the sample will stay long about 1179. 19 years.
Half life of radium-226 = 1600 years
What is half-life?
half-life, in radioactivity, the interval of time required for one-half of the atomic nuclei of a radioactive sample to decay.
Calculation of each part can be done as
a )
half-life = 1600 years
50% in 1600 years
25% in next 1600 years
so 25% in total of 3200 years .
b )
Let decay function is
[tex]m(t) = m_o e^{-kt} \ \ \ \ \ ...(i)\\[/tex]
where k is decay constant
At half life,
[tex]m(t) = \frac{m_o}{2},t= 1600\ years\\So,\ \frac{m_o}{2} = m_oe^{-k1600}\\\frac{1}{2} = e^{-k1600}\\[/tex]
applying log on both sides
[tex]ln \frac{1}{2} = lne^{-1600k}\\-0.693147 = -1600 k \\k =\frac {0.693147}{1600}\\k = 4.332\times10^{-4}\\[/tex]
substitute the value of k in equation (i)
[tex]m(t) = m_oe^{-4.332\times10^{-4t}}\\m(t) = 25e^{-0.0004332t}[/tex]
c) when t = 3000 years
[tex]m(t) = 25e^{-0.0004332t}[/tex]
[tex]m(3000) = 25e^{-0.0004332\times3000}[/tex]
remain sample after 3000 years = 6.82 mg
d) when m(t) = 15 mg
[tex]15 = 25e^{-0.0004332t}\\e^{-0.0004332 t} = \frac{15}{25}\\applying\ log\ on\ both\ side\\ln \ e^{-0.0004332t}=ln(\frac{15}{25)}\\-0.0004332t = -0.510825\\t=\frac{0.510825}{0.0004332}\\t= 1179.19 \ years[/tex]
Hence, this is the required answer.
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When sodium atoms (Na) and chlorine atoms (CI) join to make
Answer: Potassium and fluorine
Explanation:
The two rows form bonds the easiest
Answer: #1
Explanation:
Mineral reaction to stress
Answer:
Tenacity describes the reaction of a mineral to stress such as crushing, bending, breaking, or tearing. ... The majority of all minerals are brittle. An example is Quartz. (Minerals that are not brittle may be referred to as Nonbrittle minerals.)
How many mL (to the nearest mL) of 0.140-M KF solution should be added to 400. mL of 0.212-M HF to prepare a pH
Answer:
205mL of 0.140M KF solution
Explanation:
pH = 2.70 solution.
It is possible to obtain the pH of the buffer of HF-KF using the H-H equation:
pH = pKa + log [KF] / [HF]
Where pH is desire pH = 2.70
pKa is pKa of HF = 3.17
[KF] could be taken as moles of KF
And [HF] moles of HF: 400.0mL = 0.4L * (0.212mol/L) = 0.0848 moles of HF
Replacing:
2.70 = 3.17 + log [KF] / [0.0848 moles HF]
-0.47 = log [KF] / [0.0848 moles HF]
0.3388 = [KF] / [0.0848 moles HF]
[KF] = 0.02873 moles of KF must be added.
In mL using concentration of KF (0.140M):
0.02873 moles KF * (1L / 0.140 mol) = 0.205L =
205mL of 0.140M KF solutionQuestion 1 (1 point)
A chemical reaction is when substances are changed into other substances.
True or False
How does the number of atoms or molecules in a system affect its thermal energy?
A. A system with fewer atoms and molecules has more thermal energy.
B. A system with more atoms and molecules has more thermal energy.
C. The number of atoms or molecules does not affect the thermal energy of a system.
D. Thermal energy increases as the atoms and molecules in a system move more.
Answer:
D. Thermal energy increases as the atoms and molecules in a system move more.
Explanation:
Thermal energy is a form of kinetic energy possessed by molecules of a system. The measure of this kinetic energy in an atom is called heat.
The average kinetic energy of a system is the temperature.
According to the kinetic theory, the more the particles move, the more their thermal energy. Thermal energy is often predicated on the velocity of the particles of the medium.Which statement accurate describes plate tectonics?
Answer:
the lithosphere is broken into sections called plates.
Answer:
The lithosphere is broken into sections called plates.
Explanation:
edge2020
what do y'all girls find attractive on a guy?
Answer:
alot of things
Explanation:
which of the following is an example of
a physical property?
Answer:
physical property is property that you can touch, smell as it is bumpy it smells like eggs.
Explanation:
YW
Answer:
Physical properties include: appearance, texture, color, odor, melting point, boiling point, density, solubility, polarity, and many others.
Explanation:
Which best describs the energy transformation in a battery powered flash light ?
a
Chemical, to electrical, to thermal, to radiant
b
nuclear, to electrical, to thermal, to radiant
c
Mechanical, to electrical, to Thermal, to radiant
d
Chemical, to electrical, to mechanical, to radiant
Answer:
I think it's C
Explanation:
Sorry if its wrong
Answer:
C
Explanation:
Scientists discover remains of wooden structures near a Celtic runes site. What kind of testing will indicate when the stones were moved into place by the Celts?
Carbon dating
Radioactive dating
Answer:
Carbon
Explanation:
Bc i got this question on my test
Answer:
A. Carbon dating
Explanation:
I took the test proof
very
Which of the
following mineral
characteristics are
associated with
gold?
A. it is a compound
B. it is made of many elements
C. it is man made
D. it is a solid
Answer:
D,B
Explanation:
there are 79 elements in gold
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A binding protein binds to a ligand L with a Kd of 400 nM. What is the concentration of ligand when Y is (a) 0.25, (b) 0.6, (c) 0.95?
Answers: (a) 133.33nm (b) 600nm (c) 7,600nm
Answers above are correct. Please show all steps, really trying to understand.
Answer:
(a) 133.33nm
(b) 600nm
(c) 7,600nm
Explanation:
The concentration of Y can be determined by using the formula:
[tex]Y = \dfrac{[L]}{k_d+[L]}[/tex]
where;
[L] = concentration of the binding ligand.
kd = 400 nm
Thus:
When Y = 0.25; we get :
[tex]0.25 = \dfrac{[L]}{400+[L]}[/tex]
0.25 (400 + [L]) = [L]
100 + 0.25[L] = [L]
100 = [L] - 0.25 [L]
100 = 0.75 [L]
[L] = 100/0.75
[L] = 133.33 nm
At, Y = 0.6
[tex]0.6 = \dfrac{[L]}{400+[L]}[/tex]
0.6 (400 + [L]) = [L]
240 + 0.6[L] = [L]
240 = [L] - 0.6 [L]
240 = 0.4 [L]
[L] = 240/0.4
[L] = 600 nm
At, Y = 0.95
[tex]0.95 = \dfrac{[L]}{400+[L]}[/tex]
0.95 (400 + [L]) = [L]
380 + 0.95[L] = [L]
380 = [L] - 0.95 [L]
380 = 0.05 [L]
[L] = 380/0.05
[L] = 7600 nm
Calculate the number of C atoms in 0.716 mole of C?
Answer:
The answer is 4.31 × 10²³ C atoms
Explanation:
The number of C atoms can be found by using the formula
N = n × Lwhere n is the number of moles
N is the number of entities
L is the Avogadro's constant which is
6.02 × 10²³ entities
From the question we have
N = 0.716 × 6.02 × 10²³
We have the final answer as
4.31 × 10²³ C atomsHope this helps you
A geologist studies rocks. Which of Earth's spheres would a geologist be most interested in?
Answer:
Lithosphere
Explanation:
Answer:
ether the crust or lithosphere
Explanation:
Calculate the mass percentage of NaClNaCl in a solution containing 1.50 gg of NaClNaCl in 50.0 gg of water.
Answer:
%m/m = 2.9 %
Explanation:
The mass percentage (m/m %) of a solution is calculated as follows:
m/m % = mass of solute/ mass of solution x 100
The solution is composed by : solute + solvent. In this case, the solute is NaCl and the solvent is water. We have:
mass of solute = 1.50 g
mass of solvent = 50.0 g
mass of solution = mass of solute + mass of solvent = 1.50 g = 50.0 g = 51.5 g
Thus, the mass percentage of NaCl in the solution is :
% m/m = (1.50 g)/(51.5 g) x 100 = 2.91 % ≅ 2.9 %
11) Nitrogen oxides undergo many interesting reactions in the environment and in industry. Given the following information, calculate H for the overall equation:
2 NO2(g) + 1/2 O2(g) N2O5(s).
N2O5(s) 2 NO(g) + 3/2 O2(g), deltaH = 223.7 kJ
NO2(g) NO(g) + 1/2 O2(g), delataH = 57.1 kJ
delataH = ______kJ
12))))Write all coefficients, even if they are fractions or 1.)
(a) (Apply fractions as needed.)
______ _____(s) + ______ ______ (g) 5 NaCl(s)
(b) (Use the lowest possible coefficients.)
_______ _____ (s) + ______ _____(g) _____CaCl2(s)
(c) (Apply fractions as needed.)
_____ _____(g) _____O3(g)
(d) (Apply fractions as needed.)
______Mg(s) + _____ ______(s) + _____ ____(g) _____Mg3(PO4)2(s)
Answer:
one more time
Explanation:
shpuld i go