Answer:
The dependant variable
Explanation:
The dependent variable is the factor that is being tested and measured in an experiment.
Aqueous aluminium bromide and solid zinc are formed by the reaction of solid aluminum and aqueous zinc bromide. Write a balanced chemical equation for this reaction.
Answer:
3 ZnBr2(aq) + 2Al (s) ====>2AlBr3 (aq) + 3 Zn(s),
Please help, due 7:00 AM
what is the mass of an object that has a density of 8 g/cm3 and a volume of 12 cm3
Answer:
96 grams
Explanation:
Density = mass / volume Multiply both sides by the volume
density * volume = mass
mass = 8 g / cm^3 * 12 cm^3
mass = 96 grams
life scientist study life and the many processes that occur in living things____-
Answer:
life scientist study life and the many processes that occur in living things__during experiments__-
please mark me brainliest pleaseA 0.450 M solution of HCl is prepared by adding some 1.50 M HCl to a 500 mL volumetric flask and diluting to the mark with deionized water. What volume of 1.50 M HCl must be added
Answer:
150 mL of 1.50 M HCL
Explanation:
So the equation you need to solve this equation is:
M1*V1=M2*V2 --> M1= Molarity of the acid you are diluting V1= Volume of the solution you need to dilute. M2=The molarity of thee solution you have made. V2=Volume of the solution you have made
M1= 1.50 M HCL
V1= Unknown
M2=0.450 M HCL
V2= 500 mL
Simple algebra says that V1= (1.5*500)/.450 = 150 mL of 1.50 M HCL
Calculate the force needed to accelerate a 300 kg mass at 5
mls acceleration.
Explanation:
Force=mass *acceleration
F=300*5
f
F=1500N
Describe what must be happening to the particles above as the change is happening
Answer:
d
Explanation:
solids the modicual are tightly packed
liquid, more room to move around aka not so tightly packed
gas, can move where ever it wants aka not paked at all
Which of the following are considered elements:
Answer:
considered as element
Helium He
What is an atomic number
Answer:
the number of protons is called the atomic number
hope it helps you buddy
Answer: number of protons in an atom
Explanation:
This picture shows students working in a
chemistry laboratory. What could they do to make
their lab safer?
Label the test tubes and plastic cups.
Move the fire extinguisher closer to their
table.
Wear chemical protective gloves.
Reduce the clutter on the table.
Stand at the table instead of sitting. Tie long hair back.
DONE
Answer:
yes it is true they apply necessary safety measures
Answer: Label the test tubes, wear chemical protective gloves, tie long hair back
Explanation:
Just got it wrong
Arrange the following aqueous solutions in order of increasing boiling points.
0.050 m Mg(NO 3) 2; 0.100 m ethanol; 0.090 m NaCl
a. Mg(NO3) < NaCl < ethanol
b. ethanol < Mg(NO3)2 < NaCl
c. ethanol < NaCl < Mg(NO3)2
d. NaCl < ethanol < Mg(NO3)2
e. Mg(NO3)2 < ethanol < NaCl
Answer:
The correct choice is option b. ethanol < Mg(NO3)2 < NaCl
Explanation:
Ethanol = 0.100 m
Mg(NO3)2 = 0.15 m
NaCl = 0.18 m
The molar concentration of NaCl is the highest, which is why its boiling point will be the highest, too.
Each roman numeral represents a sample of a substance. Each circle represents an atom. Considering what qualifies as a pure substance, which image(s) would be considered pure substances?
III and V
V
II and IV
I and III
Answer:
III and V
Explanation:
Both of them are evenly spread homogenous mixtures.
The images that would be considered pure substances are III and V. Thus, the correct option for this question is A.
What is a Pure substance?A pure substance may be defined as a type of substance or matter that has a constant composition and properties that are constant throughout the sample.
It is scientifically found that a pure substance is typically made up of only one kind of particle and has a fixed or constant structure. According to the given diagram, images III and V signify the even distribution of the same type of atoms of molecules within the substances.
Apart from physical properties, pure substances also shares identical chemical properties as well.
Therefore, the images that would be considered pure substances are III and V. Thus, the correct option for this question is A.
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When you wash your hands or dishes, you probably don't use just water. In 5-7 sentences, explain what
you use to help you wash up, how it works, and why you think it works.
Hello! here is a paragraph you can use, that I type up to explain, make sure to not copy word for word of what I said. :)
What I use to wash up is soap. Soap has a certain ph level and includes acids and alkaline that enables water to mix and create soap foam to clean. Soap can come in many shapes and sizes, and can be either liquid, solid, or even foamy. I think soap works because when you use friction between your wet hands and the soap bar, you are rubbing the substances of the soap that clean your hands to clean your hands. I think the friction of the rubbing creates a layer of soap that can be used to clean, and when you increase friction the more change of the soap.
Have a great day,
I hope this helps!
What is the reason for the emission of light after the gas in a discharge tube is excited?
A)
photo-electric emission
Eliminate
B)
spontaneous radioactive reaction
C)
energy jumps by electrons due to excitation
D)
high energy reaction of the gas inside the tube
Answer:
c
Explanation:
took test on usa testprep
When gas in a discharge tube is excited to higher energy level after some seconds they return to the ground level by releasing energy in the form of light. Thus energy jumps by electron due to excitation is correct option.
What is gas discharge tube?A gas discharge tube is an electronic devise containing inert gases that ionizes and conducts results in emission of light.
When a potential is applied between the electrodes in a gas discharge tube, and the pressure is reduced, the gas particles inside forms a plasma of ions.
The electrons released when excited to higher energy level by absorbing energy and returns to the initial state by emitting energy in the form of light, the discharge tube glows.
The color emitted by the discharge tube vary based on the gas in the tube. Each type of gaseous ions emit different colors.
Therefore, the light emission in gas discharge tube is due to energy hike during electron excitation and then relaxing by emitting the light energy. Thus, option c is correct.
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Answer
Choice A
Answer
Choice B
Answer
Choice C
Question
A scientist hypothesizes that a new medication can reduce
the chances of catching a cold Which of these would most
likely be the dependent variable in a study involving this
medication?
//
The participants
who do not receive
the medication
Color PURPLE
The number of
participants who
catch a cold
Color YELLOW
The age of the
participants
Color GRAY
Tt remains the
T+ is purposely
It is used for
Answer:
what is the question????
Which information about an atom can a period number give you?(1 point)
A_ how many bonds it will make
B_ how many energy levels it has
C_ the number of valence electrons it has
D_ the ionic charge it forms
Answer:
A
Explanation:
Can someone do this for me!!????PLEASEEEE
Answer:
no that's worth points
Explanation:
What causes the pressure in a gas
Answer:
Gas pressure is caused when gas particles hit the walls of their container. The more often the particles hit the walls, and the faster they are moving when they do this, the higher the pressure. This is why the pressure in a tyre or balloon goes up when more air is pumped in.
HELP! 100 points if you give a valid answer and brainliest if it's detailed!
Explanation:
The extract of plant is not done in fixed proportion
it is heterogeneous
Convert 5.15 meters to inches
Answer:
202.76 inches
Explanation:
1 meter = 39.37 inches
5.15 × 39.37 = 202.7559,when rounded it's 202.76
Briefly identify a few characteristic points about the following bonds:
a. Ionic bonds
b. Covalent bonds
c. Hydrogen bonds.
Answer:
Chemical bonds hold molecules together and create temporary connections that are essential to life. Types of chemical bonds including covalent, ionic,
Explanation:
Ionic bond will form by transferring the electrons , covalent bond formed by sharing the electrons while hydrogen bond will be formed by bond between electronegative atom and hydrogen molecule.
What is ionic bond?
The chemical bond is formed when electrons are transferred from one atom to another. An ionic bond is the name for this type of relationship. Their melting and boiling points are quite high. Ionic chemicals, in other words, seem to be non-volatile.
What is covalent bond?When one non-metal reacts with just another non-metal, electrons are shared across their atoms, resulting in the development of a covalent bond. Among two or more atoms with same non-metal, a covalent connection can be established.
What is hydrogen bond?Hydrogen bonding is just a sort of dipole-dipole attraction that occurs between molecules rather than a covalently link with a hydrogen atom.
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Someone answer this please
To convert something in kilojoules to joules, you need to:
Multiply by 1,000
1
Divide by 1,000
2
Multiply by 1,000,000 3
Divide by 1,000,000
4
Answer:
Divide by 1000
Explanation:
Have a good day
Hope I helped
Multiply by 1000 .
I HOPE IT WILL HELP YOU.
HOPE your day goes great.
imagine you find a bowl filled with clear liquid in your kitchen list three liquids it might be
Answer: Three liquids that could fill a bowl with clear liquid in your kitchen could be alcohol, dish soap, juice (without pectin or pulp), sports drinks, and water (carbonated, coconut, flavored, or plain).
The following picture would be best described us
Answer:
I think its B because yeah lol but I hope you get it right
The following can be best described as a gaseous compound. The correct option is C.
What are states of matter?A state of matter is one of the various forms that matter can take in physics. In everyday life, four states of matter are visible: solid, liquid, gas, and plasma.
The elements those are gases basically at standard temperature as well as pressure are referred to as gaseous elements. The periodic table contains 11 gaseous elements.
A gas is a sample of matter that conforms to the shape of the container in which it is held and acquires a uniform density inside the container, even when gravity is present and regardless of the amount of substance in the container.
The given image depicts that the molecules of particles are at some distance from each other, this usually implies for gaseous compound.
Thus, the correct option is C.
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Find the mass of an object with 30 cm3 and has a density of 2 g/cm3 (input number only)
formation of a precipitate
formation of gas (without heat)
color change
Answer: 60 g
Explanation: Mass is the product of density and volume.
Density (2 g/cm^3)
Volume (30 cm^3)
(2 g/cm^3)*(30 cm^3) = 60 g
As discussed during the lecture, the enzyme HIV-1 reverse transcriptae (HIV-RT) plays a significant role for the HIV virus and is an important drug target. Assume a concentration [E] of 2.00 µM (i.e. 2.00 x 10-6 mol/l) for HIV-RT. Two potential drug molecules, D1 and D2, were identified, which form stable complexes with the HIV-RT.
The dissociation constant of the complex ED1 formed by HIV-RT and the drug D1 is 1.00 nM (i.e. 1.00 x 10-9 mol/l). The dissociation constant of the complex ED2 formed by HIV-RT and the drug D2 is 100 nM (i.e. 1.00 x 10-7 mol/l).
1. Compute the total concentration of [D1]tot that is needed to bind 90% of the HIV-RT at the given concentration [E]tot. Provide your answer as a numerical expression with 3 significant figures in the unit mol/l. You do NOT have to consider competition betwwen the drugs D1 and D2! They are administered separately.
2. Compute the total concentration of [D2]tot that is needed to bind 90% of the HIV-RT at the given concentration [E]tot. Provide your answer as a numerical expression with 3 significant figures in the unit mol/l.You do NOT have to consider competition betwwen the drugs D1 and D2! They are administered separately.
Answer:
C)[D]/[ED] = 5.20
D)[D]/[ED] = 5.20
E)[D']_T = 1.495* 10 ^-7 M
F)[D'] / [ED'] = 0.0579
Explanation:
E = 250 nM =2.5* 10 ^-7 mol/L , T=298.15 K
Dissociation constant of K_D = 1.3 μM (1.3 *10 ^-6 M)
E + D ⇄ ED → K_a = [ED] / [D][E] (association constant)
ED ⇄ E + D → K_D = [E][D] / [ED] (dissociation constant)
C)
[E] =2.5*10^-7 mol/L
K_D = 1.3* 10^-6 M
K_D = [E][D] / [ED] → [D]/[ED] = K_D / [E]
= [D]/[ED] = 1.3* 10 ^-6 / 2.5 *10^-7
= 13/25 * 10
=130/25 = 5.20
[D]/[ED] = 5.20
D)
ΔG =RTln Kd
ΔG_2 for E and D = 1.987 * 298.15 * ln 1.3*10^-6
ΔG_2 592.454 * [ln 1.3 +ln 10^-6]
ΔG_1 = 592.424 [0.2623 - 13.8155]
ΔG_2 = -592.424 * 13.553
ΔG_1 = -8184.633 cal/ mol
ΔG_1 = -8184.633 * 4.18 J/mol = -34244.508 J?mol
ΔG_1 = -34.245 KL/mol
so, ΔG_2 = ΔG_1 - 10.5 KJ/mol
ΔG_2 = -34.245 - 10.5
ΔG_2 = -44.745KJ / mol
ΔG_2 =RT ln K_D
-44.745 *10^3
=8.314 *298.15 lnK_D
lnK_D' = - 44745 / 2478.81 g
ln K_D' = -18.051
K_D' = -18.051
K_D' = e^-18.051
[D]/[ED] = 5.20
E)
[E] = 2.5* 10 ^-7 mol/ L = a
K_D' = [E][D] / [ED'] E +D' → ED'
K_D' = a/2(x-(a/2) / (a/2)
KD' = x - a/2
=2.447 *10^-8 = (2.5/2) * 10^-7
x=2.447 * 10^-8 + 1.25 * 10^-7
x = 2.447 *10^-8 + 1.25 * 10 ^-7
x= 10^-7 [1.25 + 0.2447]
x = 1.4947 * 10^-7
[D']_T = 1.495* 10 ^-7 M
F)
K_D' = [E][D'] / [ED']
[D'] / [ED'] = KD' / [E]
[D'] / [ED'] = 1.447 *10^-8 / 2.5* 10^-7
[D'] / [ED'] = 0.5788 * 10^-1
[D'] / [ED'] = 0.0579
Explanation:
...
Characteristics used to describe matter are called
O
A. physical properties.
O
B. chemical properties.
O
C. both A and B.
O
D. neither Anor B.
Answer:
A.physical properties
What does the -40, -42, -43, -44, -46,-48 mean for each isotope of Calcium?
the ion Te2- has how many protons
Calculate the number of kilograms of sodium fluoride needed per year for a city of 100,000 people if the daily consumption of water per person is 150.0 gallons.
Fluoridation is the process of adding fluorine to drinking water to avoid tooth decay.
The question is incomplete; the complete question is;
Fluoridation is the process of adding fluorine compounds to drinking water to help fight tooth decay. A concentration of 1 ppm of fluorine is sufficient for the purpose. (1 ppm means one part per million, or 1 g of fluorine per 1 million g of water.) The compound normally chosen for fluoridation is sodium fluoride, which is also added to some toothpastes. Calculate the quantity of sodium fluoride in kilograms needed per year for a city of 50,000 people if the daily consumption of water per person is 150 gallons.
(Sodium fluoride is 45.0 percent fluorine by mass. 1 gallon = 3.79 L; 1 year = 365 days; 1 ton = 2000 lb; I lb = 453.6 g; density of water = 1.0 g/mL.)
The quantity of sodium fluoride in kilograms needed per year for a city of 50,000 people if the daily consumption of water per person is 150 gallons is [tex]9.32 * 10^9 Kg[/tex].
From the question, we know that;
Daily consumption of water per person = 150 gallons.
Population of the city = 100,000 people
Total daily city consumption =[tex]100,000 * 150 gallons = 15 * 10^6 gallons[/tex]
Annual water consumption = [tex]15 * 10^6 gallons * 365 = 5.475 * 10^9 gallons[/tex]
1 gallon = 3.785 L = 3.785 kg
[tex]5.475 * 10^9 gallons = 5.475 * 10^9 gallons * 3.785 kg/ 1 gallon = 2.1 * 10^10 Kg[/tex]
Since sodium fluoride accounts for 45% by mass of water
Mass of sodium fluoride= [tex]0.45 * 2.1 * 10^10 Kg= 9.32 * 10^9 Kg[/tex]
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