Answer:
The answer is B
B = Petri dishes and sterile droppers
Explanation:
How many photons are produced in a laser pulse of 0.593 J at 671 nm?
Explanation:
May kwento po ba yan o yan na talaga
What gas was produced by the reaction of zinc and HCl? How did this gas behave in the presence of fire?
Answer:
The gas that was produced by the reaction of zinc and hydrochloric acid was Hydrogen gas and zinc chloride. In the presence of fire, hydrogen explodes with a popping sound. The popping sound put out the flame.
When Zn is reacts with HCl then generating tiny hydrogen bubbles as well as creating zinc chloride [tex]ZnCl_{2}[/tex] (zinc chloride).
What is hydrogen bubbles?A process known as the hydrogen bubble procedure electrolyzes conductive water containing acid / base to produce hydrogen bubbles.
What is [tex]ZnCl_{2}[/tex] (zinc chloride)[tex]ZnCl_{2}[/tex] (zinc chloride) will be formed by the reaction between the Zn (Zinc) and Cl (chlorine).
It can be written as:
[tex]Zn +Cl_{2}[/tex] → [tex]ZnCl_{2} +H_{2}[/tex].
Hence, [tex]ZnCl_{2}[/tex] (zinc chloride) and hydrogen gas will be formed during the reaction.
To know more about hydrogen bubbles.
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What’s the frequency of radiation that has a wavelength of 13 um, about the size of bacterium?
Answer:
2.3)X10^13-Hz
Explanation:
What’s the frequency of radiation that has a wavelength of 13 um, about the size of bacterium?
a micro meter is 10^-6 meter
frequency of light times wavelength = c the speed of light 3X10^8 M/sec
so
frequency times 13 X10^-6 =3X10^8 M/
so
FR3EQUENCY = 3X10^8/13X10-6
=(30/13)10^13 =2.3)X10^13-Hz
7 X
6
The most abundant element in the earth's crust is ____________ .
Answer:
Hey mate.....
Explanation:
This is ur answer....
OxygenHope it helps!
Brainliest pls!
Follow me! :D
An aqueous solution of a vanadium chloride salt is electrolyzed by a current of 3.00 A passing through the solution for 60.0 min. If 5.70 g of vanadium is produced at the cathode during this time, what is the likely formula unit for the vanadium salt
From the information in the question, the formula unit of the salt is given as VCl.
The quantity of charge produced is obtained from;
Q = It
I = current (3 A), t = time (3600 s)
Q = 3 A × 3600 s
Q = 10800 C
Now we need to find the number of electrons transferred as follows;
51 g of Vanadium is deposited by 96500n C
5.70 g is deposited by 10800 C
5.70 × 96500n = 51 × 10800
n = 51 × 10800/5.70 × 96500
n = 1
The formula of the salt is VCl.
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Is this right so far if jut correct me abs help me on how to get the first one pleade
375cm3 of a gas has a pressure of 770 mm Hg, find it Volume if the pressure is reduced to 750 mm Hg
Answer:
385 cm^3
Explanation:
375cm3 of a gas has a pressure of 770 mm Hg, find it Volume if the pressure is reduced to 750 mm Hg
if we reduce the pressure, the volume increase since since PV is constant
so the new volume = 0.375 cm^3 X 770/750 = 385 cm^3
63
ethylene glycol, an antifreeze boils at 197 ⁰C. Convert 197 ⁰C to:
⁰F =
K =
[tex]\boxed{\sf °F=\dfrac{9}{5}°C+32}[/tex]
[tex]\\ \sf\longmapsto °F=\dfrac{9}{5}(197)+32[/tex]
[tex]\\ \sf\longmapsto °F=\dfrac{1773}{5}+32[/tex]
[tex]\\ \sf\longmapsto °F=354.6+32[/tex]
[tex]\\ \sf\longmapsto °F=386.6°F[/tex]
[tex]\rule{200pt}{5pt}[/tex]
[tex]\boxed{\sf K=°C+273}[/tex]
[tex]\\ \sf\longmapsto K=197+273[/tex]
[tex]\\ \sf\longmapsto K=470K[/tex]
A solid is crushed into a powder is chimacal change or pysical change
Answer:
Physical Change
Explanation:
A solid being crushed into a powder is a physical change because a chemical change is when substances combine to create new substances.
Hope this helps :)
An atom contains 32 protons and 48 neutrons.
(a) What is its atomic number?
(b) How many electrons does it have?
(c) What is the mass of the atom?
Answer:
The answer to these are:
(A) 32
(B) If it is balanced 32
(C) 80
Explanation:
Read the following statement:
The amount of force acting on an object is equal to its mass times its acceleration.
Does the statement describe a scientific law?
No, because it is applicable to all cases in the natural world
Yes, because it is applicable to just a few cases in the natural world
No, because it describes the relationship between force and acceleration
Yes, because it describes how mass and acceleration affect force
the atomic number of magnsium is 12 this means that that its nucleus must contain
Explanation:
Since magnesium has an atomic number of 12, that means that it has 12 protons and 12 electrons when it is in normal state.
Answer:
12 protons
Explanation:
mercury fulminate is so unstable it is used in blasting caps. Can you offer an explanation for this instability
Answer:
Mercury fulminate is very sensitive to shock, friction, and sparks. ... put mercury fulminate into blasting caps for detonating dynamite.
Explanation:
What is heat of reaction? Tell me In a short description?
Answer:
The Heat of Reaction (also known and Enthalpy of Reaction) is the change in the enthalpy of a chemical reaction that occurs at a constant pressure. It is a thermodynamic unit of measurement useful for calculating the amount of energy per mole either released or produced in a reaction.
Under what condition will the result of an experiment based on a hypothesis most likely lead to a new experimentation?
Answer:
When the results do not match the experimenter's predictions.
Identify key concepts/terminologies about solutions or concentration of solutions
PLS HELP ASAP!!
identify keys concepts/terminologies about solutions or concentration of solutions.
Answer:They are the two basic solution concentration terms that you need to know.We always need to keep an account of the amount of solute in a solution.The amount of solute in the solvent is what is called the concentration of a solution.In chemistry,we define concentration of solution as the amount of solute in a solvent.
Explanation:Depending upon amount of solute present,it is called a dilute, concentrated or a saturated solution.Different substances in a given solvent have a different solubilities at the same temperature.The most common method for expressing the concentration of a solution is the percentage method
#Carry On Learning :)If a barometer were built using water (d=1.0 g/cm3) instead of mercury (d=13.6 g/cm3), would the column of water be higher than, lower than, or the same as the column of mercury at 1.00 atm? If the level is different, by what factor? Explain.
Explanation:
A more dense liquid stays lower while a less dense liquid stays higher. since water is 13.6 times less dense than mercury, the column for a barometer using water would have to be 13.6 times taller.
what is chemical reaction ?
*1. The internal energy with a system associated with the motion of particles and that can be added to a substance is called_____.
A. Thermal energy
B. Electrostatic forces
C. Temperature
D. Kinetic energy
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•
•
*2. Which statement describes the effect of adding more energy to a system, assuming a phase change does not occur?
A. The particles within the system will have greater motion, and the temperature will decrease.
B. The particles within the system will have greater motion, and the temperature will increase.
C. The particles within the system will have less motion, and the temperature will increase.
D. The particles within the system will have less motion, and the temperature will decrease.
•
•
•
*3. Which statement correctly describes how attractions that hold particles break?
A. Attractions due to electrostatic forces. When particles have low enough energy, these forces can no longer keep particles together.
B. Attractions due to gravitational forces. When particles have low enough energy, these forces can no longer keep particles together.
C. Attractions due to gravitational forces. When particles move fast enough, these forces can no longer keep particles together.
D. Attractions due to electrostatic forces. When particles move fast enough, these forces can no longer keep particles together.
•
•
•
*4. Which statement explains why a rubber band analogy is not a perfect comparison for bonds in a substance when considering phase changes?
A. For a phase change from liquid to gas, the bonds break completely and particles can move independently of each other.
B. For a phase change from liquid to gas, the bonds do not break completely and the particles can still slide past each other.
C. For a phase change from solid to liquid, the bonds break completely and particles can move independently of each other.
D. For a phase change from solid to liquid, the bonds do not break completely in the particles can still slide past each other.
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•
•
*5. The boiling point of benzene is 80°C. Which pair of samples will have the same average kinetic energy as benzene molecules?
A. Two samples of liquid benzene, one at 70°C in the other at 80°C.
B. A sample of liquid benzene at 70°C and a sample of gaseous benzene at 90°C.
C. Two samples of gaseous benzene, one at 80°C in the other at 90°C.
D. A sample of liquid benzene at 80°C and a sample of gaseous benzene at 80°C.
Answer:
1. thermal energy
2. the particles within the system will have greater motion, and the temp will increase.
3. attractions occur due to electrostatic forces. when particles move fast enough, these forces can no longer keep particles together.
4. for a phase change from a solid to liquid, the bonds do not break completely and particles call still slide past each other.
5. a sample of liquid benzene at 80°C and a sample of gaseous benzene at 80°C
Explanation:
hope this helps
Temperature is a measure of the average kinetic energy of molecules.
The particles of a substance are in constant random motion. As more thermal energy is added to the particles, the motion of the particles increases. If more energy is added to a system during phase change, the particles within the system will have greater motion, and the temperature will increase.
Attractions between particles is greater when the kinetic energy of molecules decreases. Therefore, a statement that correctly describes how attractions that hold particles break is; "attractions due to electrostatic forces. When particles move fast enough, these forces can no longer keep particles together."
The rubber analogy is commonly used to describe covalent bonds where stretching of bonds occur. This analogy is not apt in describing phase changes because for a phase change from a solid to liquid, the bonds do not break completely and particles call still slide past each other.
The average kinetic energy of molecules depend on temperature hence a sample of liquid benzene at 80°C and a sample of gaseous benzene at 80°C will have the same average kinetic energy.
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Help pls it’s so hard
Answer:
skip and read this story then complete the problem
To prepare 250.0 mL of 2.5 M KCl you will need to dilute _____ mL of 8.0 M KCl solution to a volume of 250.0 mL.
Answer:
78.125ml
Explanation:
Number of moles in 250ml of 2.5M KCl is (250÷1000)litres×2.5M so we divide these moles by 8M. The answer gotten will be in litres so multiply by 1000 to get it in ml
Someone help pls this is due today
Answer:
arrow down is gravity
Explanation:
Answer: The person above me is right
Explanation:
Have a Great day!
Explain how chemical spills on a person are handled when they are spilled :
(a) over the body
(b) in the eyes
Salt is dissolved into a water solvent Can the salt be extracted, and will it retain its properties?
A) No, it cannot be extracted through any means. It does not retain its original properties
B) Yes, it can be extracted through evaporation. It does not retain its original properties
C) Yes, it can be extracted through evaporation. It retains its original properties.
D) No, it cannot be extracted through any means. It retains its original properties.
When Salt is dissolved into a water solvent; Yes, it can be extracted through evaporation. It retains its original properties: Choice C.
The salt when dissolved in water solvent forms a solution.
They can be separated by boiling the mixture.
The solution formed is a mixture which can be separated by evaporation of water molecules do that the salt is left in the heating chamber.
Read more;
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Answer:
https://brainly.com/question/24692494
Explanation:
List of answers here
Imagine if Rutherford conducted his scattering experiment, and his prediction about the movement of alpha particles held true Which of the other models or scientific
observations would have also been confirmed?
The Bohr model would have been confirmed because it shows electrons spinning around a nucleus
The plum pudding model would have to be true as well because it shows that electrons are scattered within an atom,
The Bohr model would have been confirmed because it shows electrons occupying random positions inside the electron cloud.
The plum pudding model would have to be true as well because it shows that all positive charge is concentrated at the center of the atom
Answer:
The plum pudding model would have to be true as well because it shows that electrons are scattered within an atom.
Explanation:
I took the test and got it right :)
The plum pudding model would have to be true as well because it shows that electrons are scattered within an atom
The model of the atom proposed by Rutherford is called the nuclear model of the atom called the nuclear model of the atom. It was proposed after his famous experiment using a thin gold foil.
His previous prediction was that the alpha particles will bend or deflect around the positively charged areas of the gold atom. If this prediction came true, the plum pudding model would have to be true as well because it shows that electrons are scattered within an atom.
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what are massless particles
Answer:
particals that have no mass
Explanation:
key word maseless
For the diprotic weak acid H2A, a1=3.2×10−6 and a2=6.1×10−9 .
What is the pH of a 0.0750 M solution of H2A ?
What are the equilibrium concentrations of H2A and A2− in this solution?
In the first dissociation of H2A:
molarity H2A(aq)↔ (HA)^-(aq) + H^+(aq)
initial 0.05 m 0 m 0 m
change -x +x +x
equilibrium 0.05-x x x
we can neglect X in [H2A] as it so small compared to the 0.05
so by substitution in Ka equation:
Ka1 = [HA][H] / [H2A]
2.2x10^-6 = X^2/0.05
X = √(2.2x10^-6)*(0.05)= 1.1x10^-7
X= 3.32x10^-4 m
∴ [H2A] = 0.05 - 3.32x10^-4 = 0.0497 m
[HA] = 3.32x10^-4 m
[H] = 3.32x10^-4 m
the second dissociation of H2A: when ka2 = 8.2x10^-9
HA-(aq) ↔ A^2- (aq) + H+(aq)
at equilibrium 3.32x10^-4 y 3.32x10^-4
Ka2 = [H+][A^2-] / [HA]
8.2x10^-9 = Y(3.32x10^-4)/(3.32x10^-4)
∴y = 8.2x10^-9 m
∴[A] = 8.2x10^-9 m
PH= -㏒[H+]
= -㏒(3.32x10^-4)= 3.479
[A]=8.2x10^-9 m
[H2A] = 0.0497 ≈ 0.05 m
45.0 g of CaCl2 are dissolved in enough water so that the molarity of the solution is 1.15 M. What is the volume in mL of the solution?
Answer:
[tex]\boxed {\boxed {\sf 353 \ mL}}[/tex]
Explanation:
We are asked to find the volume in milliliters of a solution, given the mass of solute and molarity of the solution.
Molarity is a measure of concentration in moles per liter.
[tex]molarity = \frac {moles \ of \ solute}{liters \ of \ solution}[/tex]
1. Moles of SoluteWe are given the mass of the solute. We must convert the mass to moles using the molar mass (the mass of 1 mole of a substance). These values are found on the Periodic Table. They are equal to the atomic masses, but the units are grams per mole instead of atomic mass units.
Look up the molar masses of the individual elements in calcium chloride.
Ca: 40.08 g/mol Cl: 35.45 g/molThe chemical formula, CaCl₂, has a subscript of 2. There are 2 moles of chlorine in 1 mole of calcium chloride. We must multiply chlorine's molar mass by 2 before adding calcium's molar mass.
Cl₂ = 35.45 *2 = 70.9 g/mol CaCl₂= 40.08 + 70.9 = 110.98 g/molSet up a conversion factor using the molar mass.
[tex]\frac {110.98 \ g \ CaCl_2}{1 \ mol \ CaCl_2}[/tex]
Multiply by 45.0 grams of calcium chloride.
[tex]45.0 \ g \ CaCl_2 *\frac {110.98 \ g \ CaCl_2}{1 \ mol \ CaCl_2}[/tex]
Flip the conversion factor so the units of grams of calcium chloride cancel.
[tex]45.0 \ g \ CaCl_2 *\frac{1 \ mol \ CaCl_2} {110.98 \ g \ CaCl_2}[/tex]
[tex]45.0 \ *\frac{1 \ mol \ CaCl_2} {110.98}[/tex]
[tex]\frac {45.0}{110.98} \ mol \ CaCl_2= 0.405478465 \ mol \ CaCl_2[/tex]
2. Liters of SolutionNow we can find the liters of solution.
[tex]molarity = \frac {moles \ of \ solute}{liters \ of \ solution}[/tex]
molarity = 1.15 mol CaCl₂/L moles of solute = 0.405478465 mol CaCl₂liters of solution =xSubstitute the values into the formula.
[tex]1.15 \ mol \ CaCl_2/L = \frac{0.405478465 \ mol \ CaCl_2}{x}[/tex]
Cross multiply.
[tex]\frac {1.15 \ mol \ CaCl_2 /L}{1}= \frac{0.405478465 \ mol \ CaCl_2}{x}[/tex]
[tex]{1.15 \ mol \ CaCl_2 /L}*x= {0.405478465 \ mol \ CaCl_2} * 1[/tex]
Divide both sides of the equation by 1.15 moles of calcium chloride to isolate the variable x.
[tex]\frac {1.15 \ mol \ CaCl_2/L *x}{1.15 \ mol \ CaCl_2 /L}= \frac{0.405478465 \ mol \ CaCl_2 * 1 }{1.15 \ mol \ CaCl_2/L }[/tex]
[tex]x=\frac{0.405478465 \ mol \ CaCl_2 * 1 }{1.15 \ mol \ CaCl_2 /L}[/tex]
The units of moles of calcium chloride cancel.
[tex]x=\frac{0.405478465 }{1.15 \ L }[/tex]
[tex]x=0.35258997 \ L[/tex]
3. Convert to millilitersThere are 1000 milliliters in 1 liter.
[tex]\frac {1000 \ mL}{1 \ L}[/tex]
[tex]0.35258997 \ L * \frac{1000 \ mL}{ 1 \ L}[/tex]
[tex]0.35258997 * 1000 \ mL=352.58997 \ mL[/tex]
The original measurements of mass and molarity have 3 significant figures, so our answer must have the same. For the number we found, that is the ones place. The 5 in the tenth place tells us to round the 2 up to a 3.
[tex]353 \ mL[/tex]
The volume of the solution is approximately 353 milliliters.
what other solvent could have been used?
What other solvent could have been used?
water (universal solvent)acetonemethanolacetic acidethyl acetateFruit juice when boiled taste sweeter than sucrose because
Answer :see explanation
Explanation:
the sweet carbohydrate in fruit is not sucrose , it is fructose.
and fructose tastes sweeter than sucrose
fructose and glucose minus water equals sucrose
and fructose is sweeter than glucose