Answer:
the possibility of contamination in the laboratory is minimized
Explanation:
When a particular laboratory equipment is used for a given purpose, it can not be used four another purpose until it has been thoroughly washed. This is done in order to avoid contamination when the equipment is subsequently used for a different purpose.
Hence, if a laboratory equipment is not properly cleaned and stored after use, they remain contaminated and give inaccurate results when subsequently used.
please help with this question
thx
Ava wants to use an inflatable rubber raft to do a polar bear plunge on New Year’s Day. She inflates the raft to one atmosphere in her garage at room temperature, 20°C. She then drives out to the lake where she and her friends are going to swim very briefly in water at a temperature of 1°C.
( A )the decrease in temp will cause a decrease in the volume of the raft nd this drop in volume of the raft and this drop in volume may cause Ava to sink while on raft.
( B ) The decrease in temp will cause an increase in the volume of the raft and this increase in volume may cause Ava to sink while on the raft.
( C ) the decrease in temp will cause a decrease in the volume will help keep Ava afloat
( D )the decrese in temp will cause an increase in the volume of the raft and this increase in volume of the raft and this increase in volume will keep ava afloat.
Answer:
A the decrease in temp will cause a decrease in the volume of the raft and this drop in volume of the raft and this drop in volume may cause Ava to sink while on raft.
write the steps for a covalent bond for s2
Answer:
Sulfur, which only needs two electrons to complete it octet, will pick up the two electrons coming from magnesium, becoming the sulfide anion, S2− , in the process. The electrostatic force of attraction will then bring the magnesium cations and the sulfur anions together → an ionic bond i
The site of transcription initiation is the
promoter.
sigma factor.
start codon.
origin of replication.
Which of the following parts pumps the blood throughout the body?
[tex]\huge\bold\green{Answer:-}[/tex]
Both venae cavae (7) pass the deoxygenated blood to the right atrium. Blood from the right atrium (1) enters right ventricle (2) and pulmonary arteries (6) carry deoxygenated blood from right ventricle to lungs for oxygenation. Two pulmonary veins (8) come from each lung and pass oxygenated blood to left atrium (3). The left ventricle (4) pumps blood into the aorta (5) which in turn branches and delivers blood to the major body regions and organs.So, the correct answer is option A.
Bubbles started appearing in a pot of water kept on the stove. This shows the process of
(1 Point)
A. evaporation
B. condensation
O C. freezing
O C. boiling
C. boiling
when water starts boiling you will se bubbles appearing
A mercury lamp emits radiation with a wavelength of 4. 36x 105 cm. A. What is this wavelength in meters?
Can you post all the answers for "Mass and Atoms Quick Check" NO need explanation
Which statement describes the quantities that can be found using the number of moles?(1 point)
Question 1: Which statement describes the quantities that can be found using the number of moles?
Answer: It can be used to find the number of molecules, atoms, or ions.
Question 2: A scientist uses 3 g of water (H2O) in an experiment. Which option describes the first step in calculating the number of molecules in 3 g of water?
Answer: Identify the molar masses of H and O.
Question 3: The molar mass of ammonia (NH3) is 17.03 g/mol. Which expression correctly shows how to determine the number of moles of ammonia equivalent to 5 g?
Answer: 5 g×1 mol/17.03 g
Question 4: How many molecules of carbon dioxide (CO2) are there in 0.450 mol of carbon dioxide?
Answer: 2.71×1023
Question 5: When magnesium chloride (MgCl2) is dissolved in water, which statement must be true?
Answer: The sum of the mass of the Mg2+ ions and the mass of the Cl– ions must be equal to the mass of MgCl2.
The mass of an object is 240g and its volume is 60 cm3
will it sink or float
Answer:
Float
Explanation:
Becuase 240 g had more volume then the 60 cm3 which is lighter that the mass of 240 grams
Write the Noble Gas Notation for Silicone
Answer:
[Ne] 3s2 3p2
Explanation:
Neon (Ne) is the noble gas right before silicon (Si).
Then right after neon is the 3s subshell. It has two electrons and is full.
After 3s comes the 3p subshell, and silicon only has two electrons in the 3p subshell (you can just count the electrons in each subshell on your periodic table).
The Sun keeps all of the planets orbiting it because _____.
A. he Law of Ellipses states that the planets orbit the Sun in circular patterns
b. the Law of Universal Gravitation states that an increase in mass causes an increase in gravitational force
C. the Law of Harmonies states that the motion of the planets will not stop unless an outside force is applied
D. the Law of Equal Areas states that planets sweep equal areas in equal periods of time around the Sun
Answer:
a. because of how the earth circulates around the sun.
A gas tank contains 3 gases (N2, O2, and CO2). The total pressure of the gases is 825mmHg. If Pco2 = 125mmHg and Po2= 350mmHg, what is the partial pressure of N2 gas?
Answer:
350mmHg
Explanation:
Use Dalton law
Total=P gas 1+p gas 2+ P gas 3
825=P1+350+125
825=P1+475
825-475= P1
P1= 350 mm Hg
A standard solution of 112 ppm Yellow 6 dye was prepared. A 25.1 mL aliquot of the stock Yellow 6 dye was diluted to 25 mL in a volumetric flask. What is the concentration (in ppm) of this dilute Yellow 6 dye
Answer:
multiply, 112 and 25.1 then divide the answer in six
Explanation:
The concentration of of dilute yellow 6 dye is 112.448 ppm.
What is ppm solution?PPM or parts per million is a term in chemistry used to denote very low concentrations of solution.It is defined as milligrams of substance present in 1 liter of solution.
It is technically a dimensionless quantity useful for measuring smaller concentrations present in a solution.This conversion has many scientific applications .
It is how many parts a particular compound or molecule takes up within the one million part of the whole solution. It is used for describing concentrations of substances which are usually dissolved in a solvent.
For calculating ppm concentration when two solutions one with ppm concentration is known can be found out by:
ppm of solution-1 ×volume=ppm of solution-2×volume
112×251=ppm of solution-2×25
=112.44 ppm
For calculating ppm of solution both the parts of the equation must have same weight or volume.
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Jackson enjoys looking up at the night sky and writing about the variety of objects he sees. On one special occasion, he wrote in his journal that he saw a streak of light going across part of the sky. Which answer best describes what Jackson saw? * 1 point Meteorite: A cold mixture of dust and ice that develops a long tail as it nears the sun Meteor: A cold mixture of dust and ice that develops a long tail as it nears the sun Meteorite: A streak of light made when an object burns up as it enters Earths's atmosphere Meteor: A streak of light made when an object burns up as it enters Earth's atmosphere
9514 1404 393
Answer:
Meteor: A streak of light made when an object burns up as it enters Earth's atmosphere
Explanation:
A meteorite is an object that has come from space and hit Earth.
A comet is a space object that develops a tail as it nears the sun. It is believed to be a mixture of dust and ice. In general, a comet will appear stationary in the night sky, since it moves rather slowly relative the starry background.
A meteor is a space object that makes a streak of light across the sky as it burns up in the atmosphere. (It may or may not become a meteorite, depending on the degree to which it burns up.)
__
UFOs have also been known to make streaks of light when moving across the sky.
Answer:
A streak of light made when an object burns up as it enters Earth's atmosphere
Explanation:
100 % 2021
Question
Write the correct skeleton equation for the following:
fluorine gas reacts with calcium metal to form
solid calcium fluoride
Let's see
Fluorine reacts with Calcium metal to form calcium fluoride
[tex]\\ \rm\rightarrowtail Flourine+Calcium\longrightarrow CaF_2[/tex]
Write states[tex]\\ \rm\rightarrowtail Fluorine(g)+Calcium (s)\longrightarrow Calcium\: Fluoride (s)[/tex]
The chemical equation when fluorine gas reacts with calcium metal to form solid calcium fluoride is Ca + F₂[tex]\rightarrow[/tex] CaF₂.
What is chemical equation?Chemical equation is a symbolic representation of a chemical reaction which is written in the form of symbols and chemical formulas.The reactants are present on the left hand side while the products are present on the right hand side.
A plus sign is present between reactants and products if they are more than one in any case and an arrow is present pointing towards the product side which indicates the direction of the reaction .There are coefficients present next to the chemical symbols and formulas .
The first chemical equation was put forth by Jean Beguin in 1615.By making use of chemical equations the direction of reaction ,state of reactants and products can be stated. In the chemical equations even the temperature to be maintained and catalyst can be mentioned.
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A bird flies 45 meters in 3 seconds. What is its speed?
Select the correct answer from each drop-down menu. To prepare a 2 M solution of potassium nitrate (KNO3), which quantities must be measured? The mass of the and the volume of the must be measured.
Molarity determines the molar concentration of the solute dissolved in the solution. Mass and volume should be measured for the estimation of the molarity.
What is molarity?Molarity is the mass of the solute present in the litre of solution. It is also called molar concentration as it estimates the concentration of the compounds.
The unit of molarity is mol/L and can be given by the formula:
[tex]\rm Molarity(M) = \rm \dfrac{ \text{Mass of solute}}{\text{Molar mass of solute}}\times \text{Volume of Solution in L}[/tex]
Therefore, for the formation of a 2M potassium nitrate solution, the volume of the solution and mass of the solute is required.
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A volume of 75 mL of 0. 060 M NaF is mixed with 25 mL of 0. 15 M Sr(NO3)2. Calculate the concentrations in the final solution of NO3 - , Na , Sr2 , and F-. (Ksp for SrF2
For a volume of 75 mL of 0. 060 M NaF is mixed with 25 mL of 0. 15 M Sr(NO3)2, the concentrations in the final solution is mathematically given as
[NO3-] = 0.075 M[Na+] = 0.045 M[Sr2+] = 0.015 M[F-] = 0.00012 MWhat are the concentrations in the final solution of NO3 - , Na , Sr2 , and F-.?Generally, the equation for the molarity of NaF is mathematically given as
M NaF= millimoles / total volume
M NaF= = 75 x 0.060 / (75+ 25)
M NaF = 0.045
Where, Sr(NO3)2 molarity = 25 x 0.15 / (75+ 25)
Sr(NO3)2 molarity = 0.0375 M
The Chemmical reaction of Sr and F is
Sr+2 + 2 F ---> SrF2
Therefore,Ksp = [Sr+2] [F-]^2
2.0 x 10^-10 = 0.015 [F-]^2
[F-] = 1.2 x 10^-4 M
In conclusion, the concentrations are
[NO3-] = 0.075 M[Na+] = 0.045 M[Sr2+] = 0.015 M[F-] = 0.00012 MRead more about Concentration
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A student conducts an investigation to determine which magnet is strongest: the horseshoe, the bar, or the ring. The student tests each magnet one time using the same metal object and announces that the bar magnet is strongest. What is wrong with the student's reasoning?
Answer:
Each magnet should have been tested on many different magnetizable materials
Explanation:
In designing an experiment such as that outlined above, the experimental design should have included many different magnetizable materials.
All the types of magnets; the horseshoe, the bar, and the ring magnet should have been tested using many different magnetizable materials apart from the metal object. By so doing, the strongest magnet can be effectively determined without bias because it will attract the greatest number of magnetizable materials.
Again, the shape of the magnet affects its ability to attract objects. Hence, different shapes of magnets can not effectively be compared for relative magnetic strength.
Explanation:
bold is strong
Define Magnetic force and Magnetic field
Answer:A magnetic field is a vector field that describes the magnetic influence on moving electric charges, electric currents, and magnetized materials. A charge that is moving in a magnetic field experiences a force perpendicular to its own velocity and to the magnetic field
Explanation:hope this helps :DD
In a chromatography experiment, how do you identify the components of an unknown mixture?.
The components in an unknown mixture are separated based on differences in their speed along the stationary phase.
What is chromatography?Chromatography is a separation technique which us used to separate the components of a colored mixture based on the ability of the components to move along a medium at different speeds.
The components of a colored mixture have different densities and different adsorption properties.
Thus they move at different speeds over the stationary phase of the chromatogram.
Therefore, the components of an unknown mixture are separated based on differences in their velocity in the stationary phase.
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When any reversible reaction is at equilibrium, what conditions are necessarily true?.
Answer:
Reversible reactions that happen in a closed system eventually reach equilibrium. At equilibrium, the concentrations of reactants and products do not change. But the forward and reverse reactions have not stopped - they are still going on, and at the same rate as each other.
When any reversible reaction is at equilibrium, the conditions are necessarily true are the amount of reactant and products stops changing, and the rate of forward reaction equals rate of backward reaction. The correct options are B and D.
What is a reversible reaction?A reversible reaction occurs when the conversion of reactants to products and the conversion of products to reactants occur at the same time.
A and B can react to form C and D, or C and D can react to form A and B in the reverse reaction. In thermodynamics, this is not the same as a reversible process.
In a closed system, reversible reactions eventually reach equilibrium. The concentrations of both reactants and products remain constant at equilibrium.
But the forward and reverse reactions have not stopped; they are still occurring at the same rate.
Reversible reactions continue until equilibrium is reached, which means that the amounts of reactant and product are balanced.
Thus, the correct options are B and D.
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Your question seems incomplete, the missing options are attached below as image:
Predict the fact is all great white sharks were removed from an aquatic ecosystems. Write a short radio ad explaining why sharks should be protected .
At 1 atm, how much energy is required to heat 59.0 g H2O(s) at −22.0 ∘C to H2O(g) at 141.0 ∘C? STRATEGY: Calculate the energy needed for each temperature change or phase change individually. a. The energy needed to heat 59.0 g H2O(s) from −22.0 ∘C to its melting point. b. The energy needed to melt 59.0 g H2O(s) at its melting point. c. The energy needed to heat 59.0 g H2O(l) from the melting point to the boiling point. d. The energy needed to boil 59.0 g H2O(l) at its boiling point. e. The energy needed to heat 59.0 g H2O(g) from the boiling point to 141.0 ∘C. Sum the energies from each step and convert to kilojoules. Step 1. a. Going from −22.0 ∘C to the melting point of H2O (0 ∘C) is a temperature change of 22.0 ∘C. How much energy is needed to heat 59.0 g H2O(s) by 22.0 ∘C if its specific heat is 2.087 J/(g× ∘C)?
Answer:
The answer is "2736.1 J"
Explanation:
[tex]m= 59.0 \ g\\\\t_2 = -22\\\\\Delta t= t_1-t_2\\\\[/tex]
[tex]= 0-(-22)\\= 22[/tex]
specific heat for ice = 2.108 [tex]\frac{J}{gk} \\[/tex]
Formula:
[tex]\bold{Q= mc \Delta t} \\[/tex]
[tex]= 59 \times 2.108 \times 22\\\\= 2736.1 \ \ J[/tex]
What does it mean when something on the internet “goes viral”? How is this similar to a virus spreading through a community?
Please help !!!!
Answer:
When something goes viral on the internet, it gets really popular. As it gets more and more popular, more people see it. For instance, as a video becomes viewed more and more, it is recommended to more and more people to watch.
This is a good example of how a virus spreads. As more and more people receive the virus in a community, more and more people get it. Then, the more likely it is to spread to more people.
Explanation:
I hope this helps. I didn't know if you wanted a 500 word essay or something...
Answer:
it's when you post something and everyone likes it that's what viral means
10 elements and what you know about their properties and reactions.
Answer:
Hydrogen. H.
Helium. He.
Lithium. Li.
Beryllium. Be.
Boron. B.
Carbon. C.
Nitrogen. N.
Oxygen. O.
Fluorine
Neon
Explanation:
2. Does the aluminum sample (the can) contain more than, (less than or exactly one mole of aluminum? Support answer with calculation.
Answer:
than, (less than or exactly one mole
!!!!CHEMISTRY HELP NEEDED 25 POINTS!!!!
Use the equation for Charles’s Law to calculate the following. (2pts)
A balloon is filled up to 1 liter at a temperature of 294.15K. The balloon is then placed in a freezer for 24 hours at a temperature of 273.15K.
What is the volume of the balloon when it is taken out?
Answer:
It had changed by .001 liters because of the way that cold air can't evaporate more than .5 liters of air
Explanation:
18 points ! Kinetic Molecular Theory has to do with
A. the identity of gas particles.
B. the pressure of gas particles.
C. the motion of gas particles.
D. the volume of gas particles.
Answer:
C. the motion of gas particles.
Explanation:
The kinetic molecular theory is a simple but very effective model that effectively explains ideal gas behavior. The theory assumes that gases consist of widely separated molecules of negligible volume that are in constant motion, colliding elastically with one another and the walls of their container with average velocities determined by their absolute temperatures.
10. The property of water that accounts for its' ability bead up into round drops is
a. Adhesion
b. Capillary action
b. Cohesion
d. Dispersion forces
Answer:
c. Cohesion
Explanation:
Hope this helps and have a nice day