Compounds are made of more than one element hence water is made of 2 Hydrogen and one Oxygen, but nacent Hydrogen is single hence it is an element.
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
1. Distinguish between a mixture and a pure substance.
Answer:
1)Mixture is the combination of substance
2)There are two types of mixture such as heterogeneous mixture and homogeneous mixture
3)foreg=Salt solution ,sedimentation
Pure substance
1)Pure substances are also called elements
2)They are made up of small atoms
3)for eg= oxygen,Venadium ,Iron,Oxygen
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.
To find more about gas-discharge tube, refer the link below:
https://brainly.com/question/5468708
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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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what's the basic oxide
Answer:
Basic oxides are oxides that show basic properties in opposition to acidic oxides and that either react with water to form a base; or react with an acid to form a salt and water which are called neutralization reactions.
Explanation:
Mark me as brainiliest
Explanation:
A basic oxide is an oxide that shows basic properties in opposition to acidic oxides and that either ⁕reacts with water to form a base; or ⁕reacts with an acid to form a salt.
Ammonium carbonate solution is added to dilute nitric acid. What is the balanced chemical equation?
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:
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!
Musical instruments like trumpets and trombones are made from an alloy called brass. Brass is composed of copper and zinc atoms and appears homogeneous under an optical microscope. The approximate composition of most brass objects is a 2:1 ratio of copper to zinc atoms, but the exact ratio varies somewhat from one piece of brass to another. (a) Would you classify brass as an element, a compound, a homogeneous mixture, or a heterogeneous mixture
Answer:
There are various substances found in nature, which are classified as an element, compound, and mixtures. Elements are pure substances, which are found in the simplest form, compounds are formed by the combining of two or more atoms of the same or different elements. Mixtures are categorized into homogenous and heterogenous, which are based on the composition of the mixture.
Explanation:
The homogenous mixtures are defined as the mixtures in which substances or components are evenly distributed and cannot be distinguished by each other. For example, detergent, air, and water. Alloys are also considered homogenous mixtures because the elements are mixed in some particular ratio. For instance, brass and steel are such types of homogenous alloys. In brass, the solid solution of copper and zinc are mixed in a specific ratio (2:1). However, the different instruments have different ratios of brass. The brass is classified as a homogenous mixture. In contrast, heterogeneous mixtures are those in which the composition of substances is not uniform. For example, oil and water.
Which of the following best describes the make up of Saturn's rings?(1 point) solid bands of sand and dust that formed from the start of the universe solid bands of sand and dust that formed from the start of the universe material from comets that have passed through Saturn's atmosphere material from comets that have passed through Saturn's atmosphere dust, rock, and ice particles that orbit due to Saturn's gravity dust, rock, and ice particles that orbit due to Saturn's gravity debris and rocks from other planets that orbit around Saturn
Answer:
Which of the following best describes the make up of Saturn's rings?(1 point) solid bands of sand and dust that formed from the start of the universe solid bands of sand and dust that formed from the start of the universe material from comets that have passed through Saturn's atmosphere material from comets that have passed through Saturn's atmosphere dust, rock, and ice particles that orbit due to Saturn's gravity dust, rock, and ice particles that orbit due to Saturn's gravity debris and rocks from other planets that orbit around Saturn
The make up of Saturn's ring are dust, rock, and ice particles that orbit due to Saturn's gravity"
Saturn is one of the 9 planets of the solar system. It is considered to be the second largest planet.
Saturn has seven large rings orbiting around it. These rings are believed to be pieces of comets, asteroids, or shattered moons that broke up before they reached the planet. And this shattered comets or asteroid are believed to be torn apart by Saturn's powerful gravity.
These comets or asteroids are made of billions of small chunks of ice and rocks which are covered or coated with other small materials such as dust particles.
Thus, the correct option that matches the above explanation is "dust, rock, and ice particles that orbit due to Saturn's gravity"
Learn more here: https://brainly.com/question/24569357
Calculate the force needed to accelerate a 300 kg mass at 5
mls acceleration.
Explanation:
Force=mass *acceleration
F=300*5
f
F=1500N
What does the -40, -42, -43, -44, -46,-48 mean for each isotope of Calcium?
How does increasing the temperature of a liquid below the boiling point affect
the motion of the particles in the liquid?
To scientific notation 5.029m
Answer:
5.029 × 100
Explanation:
HELP I WILL MARK YOU AS THE BRAINLIEST ANSWER
The atomic radii of elements on the periodic table generally _______ from left to right and _______ from top to bottom.
A.
increase; decrease
B.
decrease; increase
C.
stay the same; increase
D.
increase; increase
Hey there! Here is the answer:
B.) decrease; increase
Here's why:
As you move from left to right across a period on the periodic table the size of an atom will decrease. As you move from top to bottom down a group on the periodic table the size of an atom will increase.
I really hope this answer helps you out! :)
Please help me please find the answer
Please do this
Please do this
Plzz
Plzz
Total distance=60m+40m=100m
Total Time=6+4=10s
#a
[tex]\boxed{\sf Speed=\dfrac{Distance}{Time}}[/tex]
[tex]\\ \sf\longmapsto Speed=\dfrac{100}{10}[/tex]
[tex]\\ \sf\longmapsto 10m/s[/tex]
#b
Displacement=AC=60m
[tex]\\ \sf\longmapsto Velocity=\dfrac{Displacement}{Time}[/tex]
[tex]\\ \sf\longmapsto Velocity=\dfrac{60}{10}[/tex]
[tex]\\ \sf\longmapsto 6m/s[/tex]
#C
Distance=60m
time=5s
[tex]\\ \sf\longmapsto Velocity=\dfrac{60}{5}=12m/s[/tex]
#d
The velocity of A to C is greater than Velocity from C to A
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????
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:
...
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
Atoms are mostly made up of the
between electrons and the nucleus.
Answer:
yes
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.
A 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
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
which term best describes the role of hydrogen gas in the formation of a water molecule
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 ion Te2- has how many protons
A rabbit has a mass of 2kg. What is its weight
Answer:
weight = Mass × gravity
P= m × g
P=mg
Weight (P) = ? , Mass (m) = 2 kg , gravity (g) = 9.8 m/s²
P= mg
p = 2 × 9.8
P= 19.6 kg.m/s²
P= 19.6 N
I hope I helped you^_^
Which of the following are considered elements:
Answer:
considered as element
Helium He
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
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.
