Answer:
As a result, to prepare 250 ml of 0.20M NaCl, take 50 ml of 1.0M NaCl solution and add 200 ml of water.
Explanation:
Hey does anyone know how to find valence electrons in any periodic table element?
Answer:
Number of valence electrons = Group number of the element on the periodic table.
Explanation:
Hope that helps ^^
If you zoom all the way in, what is the smallest object on the head of the pin?
3. in a purity check for industrial diamonds, a 10.25 degrees carat (1carat = 0.2000g) diamond is heated to 74.21 °c and immersed in 26.05 g of water in a constant pressure calorimeter. the initial temperature of the water is 27.20 ^ c . the final temperature of the system is 27.65 °c. calculate the specific heat of the diamond.
From the calculations, the specific heat capacity of diamond is 42.36 J/Kg/°C.
What is specific heat capacity?The specific heat capacity is the heat absorbed or emitted when 1Kg of a susbtance is heated such that its temperature is increased by 1 K.
Now;
Mass of water = 26.05 g or 0.026 Kg
Mass of diamond = 2.05 g or 0.00205 Kg
specific heat capacity of water = 4200 J/Kg/°C
specific heat capacity of diamond = ?
Initial temperature of water = 27.20°C
Initial temperature of diamond =74.21 °c
Final temperature of the diamond and water = 27.65 °c
Heat lost by diamond = heat gained by water
mcdT = mcdT
0.00205 Kg * c * ( 74.21 °c - 27.65 °c ) = 0.026 Kg * 4200 J/Kg/°C * (27.65 °c - 27.20°C)
0.116c = 4.914
c = 4.914/0.116
c = 42.36 J/Kg/°C
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Match the following.
1.
an agreement to temporarily cease fighting
recession
2. an economic setback in commercial and industrial activity
reparations
3. indemnities paid by defeated countries for acts of war
armistice
Answer:
The answer is number 1
Explanation:
this is because cease means to stop,and recession also means to squeeze
How did Ernest Rutherford's experiment relate to J.J. Thomson's work?
A Rutherford looked for magnetic fields, while Thomson looked for electric
fields.
B Rutherford repeated Thomson's experiment and confirmed the results.
C Rutherford tested a conclusion based on Thomson's results.
D Rutherford had not known about Thomson's experiment.
Answer:
D
Explanation:
I am sorry if wrong
Answer:
C
Explanation:
I tested the other answer and it was wrong, when I put C I got 100... Your welcome!
The element copper has naturally occurring isotopes with mass numbers of 63 and 65. The relative abundance and atomic masses are:
69.2% for a mass of 63
30.8% for a mass of 65.
Answer:
Take the weighted average of the individual isotopes.
Explanation:
63
C
u
has
69.2
%
abundance.
65
C
u
has
30.8
%
abundance.
So, the weighted average is
62.93
×
69.2
%
+
64.93
×
30.8
%
=
63.55
amu
.
If we look at the Periodic Table, copper metal (a mixture of isotopes but
63
C
u
and
65
C
u
predominate) has an approximate atomic mass of
63.55
g
⋅
m
o
l
−
1
, so we know we are right.
Explain why the equation ( x - 4 ) ^2 - 28 =8 has two solutions. Then solve the equation to find the solutions. Show your work. ( Will Mark Brainliest). Please only answer if you are 100% sure.
Taking into account the discriminant and quadratic formula:
As Δ> 0 the function has two real roots or solutions.The solutions are x1= 10 and x2= -2.Zeros or solutions of a function
The points where a polynomial function crosses the axis of the independent term (x) represent the so-called zeros of the function.
That is, the zeros represent the roots of the polynomial equation that is obtained by making f(x)=0.
In summary, the roots or zeros of the quadratic function are those values of x for which the expression is equal to 0. Graphically, the roots correspond to the abscissa of the points where the parabola intersects the x-axis.
DiscriminantThe function f(x) = ax² + bx + c
with a, b, c real numbers and a ≠ 0, is a function quadratic expressed in its polynomial form (It is so called because the function is expressed by a polynomial).
The following expression is called discriminant:
Δ= b²- 4×a×c
The discriminant determines the amount of roots or solutions of the function.
Then:
If Δ <0 the function has no real roots and its graph does not intersect the x-axis.If Δ> 0 the function has two real roots and its graph intersects the x-axis at two points.If Δ = 0 the function has a real root and its graph intersects the x-axis at a single point that coincides with its vertex. In this case the function is said to have a double root.Amount of solutions of function (x - 4)² - 28 =8The function (x - 4)² - 28 =8 can be expressed as:
(x - 4)² - 28 -8= 0
(x - 4)² - 36= 0
x²- 8x + 16 - 36= 0
x²- 8x + 16 - 36= 0
x²- 8x - 20= 0
Being:
a= 1b= -8c= -20the amount of solutions are calculated as:
Δ= (-8)²- 4×1×(-20)
Δ= 144
As Δ> 0 the function has two real roots or solutions and its graph intersects the x-axis at two points.
Solutions of a cuadratic functionIn a quadratic function that has the form:
f(x)= ax² + bx + c
the zeros or solutions are calculated by:
[tex]x1,x2=\frac{-b+-\sqrt{b^{2}-4ac } }{2a}[/tex]
Solutions of function (x - 4)² - 28 =8The function (x - 4)² - 28 =8 can be expressed as x²- 8x - 20= 0
Being:
a= 1b= -8c= -20the solutions of the function are calculated as:
[tex]x1=\frac{-(-8)+\sqrt{(-8)^{2}-4x1x(-20) } }{2x1}[/tex]
[tex]x1=\frac{-(-8)+\sqrt{144 } }{2x1}[/tex]
[tex]x1=\frac{8+\sqrt{144 } }{2}[/tex]
[tex]x1=\frac{8+12 }{2}[/tex]
[tex]x1=\frac{20}{2}[/tex]
x1= 10
and
[tex]x2=\frac{-(-8)-\sqrt{(-8)^{2}-4x1x(-20) } }{2x1}[/tex]
[tex]x2=\frac{-(-8)-\sqrt{144 } }{2x1}[/tex]
[tex]x2=\frac{8-\sqrt{144 } }{2}[/tex]
[tex]x2=\frac{8-12}{2}[/tex]
[tex]x2=\frac{-4}{2}[/tex]
x1= -2
Finally, the quadratic function (x - 4)² - 28 =8 has two solutions and the solutions are x1= 10 and x2= -2.
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Help Please
10.
In order to do work on an object, what is true about the force that must be exerted?
The force must be in a direction opposite to Earth’s gravitational force.
The force must be the maximum amount of force one is able to exert.
The force must be in the same direction as the object’s motion.
The force must be quick and deliberate.
Answer:
The force must be in the same direction as the object’s motion
Explanation:
Force is a physical quantity.
It is defined as the force applied to a body to move it in the direction of the force applied.
Force = mass x acceleration.
Force results in the acceleration of a body. Force causes the change in position of a body and it moves it towards the direction of the applied force. A force is a vector quantity having both magnitude and direction.So, option is C is the correct choice.
I need help filling out this table, please help ASAP
Answer:
A-20 B-40 C-Ca D-10 E-9 F-F
Explanation:
----------------------------------------------atomic number= no.of protonsand mass no.= no. of protons+no. of neutrons__________________________A= 20B= 40C= caD= 10E= 9F=FExplain the difference between a metal and a nonmetal
WILL GET BRAINLIEST!!!!!
Study the reaction.
2H2 + O2 + 2H20
What is the mole ratio for the reaction between oxygen (O2) and hydrogen (Hz)?
O 2 oxygen to 1 hydrogen
O 1 oxygen to 2 hydrogen
O 4 oxygen to 2 hydrogen
O 2 oxygen to 2 hydrogen
HELPPP
Choose the atom or ion that is larger.
Select one:
a. S
b. S-2
Answer:
In general, anions are larger than the corresponding neutral atom, since adding electrons increases the number of electron-electron repulsion interactions that take place. Cations are smaller than the corresponding neutral atoms, since the valence electrons, which are furthest away from the nucleus, are lost.
Explanation:
The ion S⁻² (sulfide ion) is larger than the atom S (sulfur atom).
b. S⁻²
Atoms are composed of a nucleus at the center, containing protons and neutrons, and a cloud of electrons surrounding the nucleus. The size of an atom is determined mainly by the arrangement and energy levels of its electrons.
When an atom gains electrons to become an ion, it undergoes a process called electron gain or electron attachment. In this case, sulfur (S) has six valence electrons (electron configuration: 1s² 2s² 2p⁶ 3s² 3p⁴). It tends to gain two electrons to achieve a stable electron configuration similar to the nearest noble gas, argon (Ar: 1s² 2s² 2p⁶ 3s² 3p⁶). By gaining two electrons, sulfur forms the sulfide ion (S⁻²), which has an electron configuration of 1s² 2s² 2p⁶ 3s² 3p⁶.
When an atom gains electrons to become an ion, it forms a negatively charged ion, and this is the case for S⁻². The extra electrons in the ion's electron cloud cause repulsion, leading to an increase in the ion's size compared to the neutral atom. In other words, the addition of two extra electrons in the S⁻² ion increases its electron cloud's size, making it larger than the S atom.
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The boiling points of different substances are given in the table below.
Substance
Boiling point (°C)
Acetic acid
118.1
Benzene
80.2
Chloroform
61.2
Water
100.0
Which substance most likely has the strongest intermolecular forces?
acetic acid
benzene
chloroform
water
Answer:
A) acetic acid
Explanation:
Acetic acid most likely has the strongest intermolecular forces. Hence, option A is correct.
What is the boiling point?The boiling point of a substance is the point at which the vapour pressure of a liquid is equal to the surrounding pressure and water is 313k for absolute temperature and 212°F for Fahrenheit.
The intermolecular force of attraction depends on the strength or extent of Hydrogen bonding present in a substance.
Benzene and chloroform do not have hydrogen bonding being non-polar molecules.
Water has hydrogen bonding being polar.
However acetic acid being the most polar has the maximum hydrogen bonding.
Thus acetic acid has the strongest intermolecular forces of attraction.
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Please help meee ( please answer all )
Answer:
Au = Element
NaCl = Compound
Salad = Heterogeneous
NaCl & Water = Homogeneous
If a sound wave speeds up and its frequency does not change, what happens to the wavelength?
Answer: No, the speed of propagation is constant in a given medium; only the wavelength changes as the frequency changes.
Explanation:
A 65.0 g sample of copper (specific heat = 0.20 J/g °C) is heated to 97.6 °C and then
placed in a container of water at 20 °C. The final temperature of the water and copper is
24.9 °C. What is the mass of the water in the container, assuming that all the heat lost
by the copper is gained by the water?
A 65.0 g sample of copper at 97.6 °C is added to 46.1 g of water at 20 °C, reaching a final temperature of 24.9 °C.
What does the law of conservation of energy state?In physics and chemistry, the law of conservation of energy states that the total energy of an isolated system remains constant; it is said to be conserved over time.
Step 1: Calculate the heat lost by the sample of copper.A 65.0 g (m) sample of copper is cooled from 97.6 °C to 24.9 °C. Given that its specific heat (c) is 0.20 J/g.°C, we can calculate the heat (Q) lost using the following expression.
Q(Cu) = c(Cu) × m(Cu) × ΔT
Q(Cu) = (0.20 J/g.°C) × 65.0 °C × (24.9 °C - 97.6 °C) = -945 J
Step 2: Calculate the heat gained by the water (Qw).We will use the law of conservation of energy.
Qw + Q(Cu) = 0
Qw = -Q(Cu) = 945 J
Step 3: Calculate the mass of water.We will use the same expression as in Step 1.
Qw = c(w) × m(w) × ΔT
m(w) = Qw / c(w) × ΔT
m(w) = 945 J / (4.18 J&g.°C) × (24.9 °C - 20 °C) = 46.1 g
A 65.0 g sample of copper at 97.6 °C is added to 46.1 g of water at 20 °C, reaching a final temperature of 24.9 °C.
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Which has the highest viscosity? Why? water b. tea c. milk d. honey
Answer:
Honey
Explanation:
i know why but at the same time i don't. i know that water, tea, and milk are very fluid however honey is sticky and isn't AS FLUID as the others.
Therefore, honey as the highest viscosity.
Which process is separating out solute from a solvent through evaporation?.
Crystallisation
(used to separate solids from a solution)
Hope this helps!
When an object moves, stops moving, changes speed, or changes direction, how do
scien sts describe that condition?
Which of theses best explains whether alchemy is a science or pseudoscience?
when was the first light bulb made?
Answer:
1802
Explanation:
Humphry Davy invented the first electric light
Answer:
1806
Explanation:
The very first light bulb was not invented by Thomas Edison, but by British inventor Humphry Davy in 1806. His devices created an arc of electricity between electrodes, creating a very bright light. While far too dangerous to use at home, they were used in public spaces and commercially.
Hope this helps! :)
PLEASE MARK ME AS BRAINLIEST I REALLY WANT TO LEVEL UP
How does the temperature of water change when it is placed in a freezer and
then begins to freeze?
A: It decreases first and then increases.
B. It increases first and then remains constant.
C. It decreases first and then remains constant.
D. It increases first and then decreases.
Answer:
It decreases first and then remains constant.
Explanation:
Answer:
It decreases first and then remains constant.
Explanation:
The end of one bar magnet is placed near the end of another bar magnet. The two ends seem to push each other apart. Which of these statements is true?A.The two ends are like poles.B.The two ends are unlike poles.C.There are like charges on the two ends.D.There are unlike charges on the two ends
Answer:
A.The two ends are like poles
Explanation:
Magnets are composed of a north pole and a south pole. If two like poles of a magnetic are placed near each other, the two ends seem to push apart.
The reason for this is that, when like poles of two magnets are made to face each other, the lines of forces are in opposite directions, hence the magnets repel.
If unlike poles of two bar magnets are made to face each other, the magnetic lines of force are now in the same direction therefore the unlike poles attract each other.
Zi notices the spilled product, and comments that it looks different from the original ingredients. Carlotta explains that all substances have distinctive physical and chemical properties; for example, _____ are examples of physical properties.
Density, Melting point, Boiling point and Hardness are examples of physical properties.
What is physical properties?A physical property refers to that property which is measurable and whose value indicates a state of a physical system. Examples of physical properties are Density, Melting point, Boiling point and Hardness so we can conclude that Density, Melting point, Boiling point and Hardness are examples of physical properties.
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Calculate the pOH of this solution. Round to the nearest hundredth. PH = 1. 90 pOH =.
Answer:
it's 12.10
Explanation:
pH is the potential of hydrogen ions. pOH is the potential of hydroxide ions. The pOH of this solution is 12.10.
What is pH and pOH ?pH is the potential of hydrogen ions. pOH is the potential of hydroxide ions.
It is a scale used to determine the solution's hydrogen ion ( H⁺ ) concentration. It is a scale used to determine the solution's hydroxide ion ( OH⁻ ) concentration.
The difference between the two is that [OH-] represents the concentration of [OH-] or the molarity of OH-. It basically represents the concentration of OH- that is produced when a strong base reacts with water for example. pOH is a value that represents the basicity of a solution.
pH + pOH = 14
1.90 + pOH =14
pOH = 14 - 1.90
pOH = 12.10
Thus, the pOH of this solution is 12.10.
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someone please help me i dont understand how too do these
Answer:
0.55
Explanation:
When multiplying values, the number of significant figures in the answer should be the same as the number with the lowest sig figs in the problem which in this case is 2 sig figs (0.17)
3.22 * 0.17 = .5474
Rounded to 2 sig figs = 0.55
1. What is a metal replacement reaction?
Answer:
a reaction in which one element is substituted for another element in a compound
Explanation:
Elements in the same period have the same ________________________.
To make the future development more eco-friendly and decrease soil erosion,
choose one of the following recommendations:
Answer:
build better enclosures to decrease overgrazing by livestock.
Explanation:
What type of chemical reaction is the following: CH4 + O2 ➜ CO2 + H2O
Complete combustion of an alkane (methane)
You're essentially burning CH4 in the excess presence of oxygen gas, which results in the liberation of water and carbon dioxide