Answer:
True
Explanation:
A physical change is a change of state. So when ice melts it changes from a solid to a liquid so it is a physical change
(answered on edge)
Calculate the percent by mass of each element.
%N = 35 %
%H = 5.0 %
%O = 60 %
Answer:
N=35%. so 35/100*7 =2.45%
H=5.0 so 5/100*1=0.05%
o=60% so 60/100*8=4.8%
A pupil has drawn the electronic structure of fluorine and the diagram is shown below. However,
mistakes have been made. State three mistakes that have been made.
The first shell can only hold 2 electrons, but the pupil placed in 8 electrons.
The second shell can hold up to 8 electrons, but the pupil only placed in 2 electrons.
Flourine only has 9 total electrons, yet there are 10 electrons in the diagram.
Answer:
Explanation:
In the Fluorine atom there are 2 electrons in the innermost shell and 7 i the outer shell.
PLS GUYS ITS FOR 10TH GRADE CHEM
Answer:
1. 2.63x10^6
2. 39.2
Both answers have been rounded
What is the temperature of 0.5 moles of water vapor that occupies 120 dm3 and applies a pressure of 15,000 Pa to its container?
A. 433.21 K
B. 5.19 K
C. 7.52 K
D. 108.3 K
Reset Selection
Answer:
The answer is C. 7.52 K
Explanation:
hope it helps
WHICH STATEMENT BEST REPRESENTS A HYPOTHESIS
Answer:
D
Explanation:
Hypotheses are educated guesses, and the best answer is the one with an if, as it indicates that it's a guess.
Answer:
letter b should be the answer
Pesticides and fertilizers are a major cause of
O air pollution
O acid rain
o the greenhouse effect
O groundwater pollution
Answer:
it means air pollution Environment. The chemicals and nutrients found in fertilizers, while beneficial for agricultural crops, can be lethal in high doses for fish, birds and other wildlife. Pesticides, designed to kill pests chemically, are also dangerous when leached into soil or groundwater supplies.
One the first chemistry test. 12 students got As, 18 students got Bs, and 20 students got Cs.
a. What is the percentage of students received Bs.
b. What is the percentage of students who received Cs?
Express your answer to the ones place.
Answer:
A. 36 percent recieved Bs
B. 40 percent of students received Cs
Explanation:
Amount of students: 12+18+20=50
Students with Bs: (18÷50) x 100 = 36%
Students with C's: (20÷50) x100 = 40%
On the first chemistry test 12 students got A, 18 students got B, and 20 student got C. Thus the percentage of students received B is 0.36 and percentage of students received c is 0.40
What is the percentage of students received B and C?In mathematics, a number or ratio expressed as a fraction of 100. It is often denoted using the percent sign %. A percentage is a dimension less unit and it has no unit.
In above question 12 student got A, 18 student got B, and 20 student got C.
So total number of student = 12 + 18 + 20 = 50.
Then the percentage of students received B is as follows:-
Percentage of students who got B = (student who got B/Total number of student) X 100.
=(18/50) X 100
= 36%
Now percentage of students who got C = (No of students who got C/Total students)X100
=(20/50) X 100
=40%.
Therefore,On the first chemistry test 12 students got A, 18 students got B, and 20 student got C. Thus the percentage of students received B is 0.36 and percentage of students received c is 0.40 percentage of students who got B is 36% and percentage of students who got C is 40%
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Please help
I need answers now
Answer:
this is my answer.........
Which would increase the reaction rate?
O A. Decreasing the reactant concentrations
B. Removing heat from the system
O C. Adding a catalyst
O D. Lowering the value of k
Answer:
C
Explanation:
C. Adding a catalyst would increase the reaction rate.
What is a catalyst?A catalyst is a substance that increases the rate of a chemical reaction by lowering the activation energy required for the reaction to occur.
A catalyst enhances the probability of successful collisions between reactant molecules, which raises the pace of the reaction by offering an additional avenue for the reaction to occur.
As there would be fewer reactant molecules accessible to react with one another, decreasing reactant concentrations would result in a slower pace of reaction.
Due to the fact that chemical reactions often require energy to take place, eliminating heat from the system would also slow down the reaction rate. A lower value for k would result in a lower rate constant, which would lower the response rate.
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explain why crude oil is a fossil fuel
Scientific notation ? Please help
(5.55 x 10^15) x (8.88 x 10^18)
Explanation:
I first take back the numbers to their original forms that is to say (5.55×10^15) = 5550000000000000 and (8.88×10^18) = 8880000000000000000 therefore the difference of the two will be 887445 which is notated to (8.87445×10^5)
Answer: (8.87445×10^5)
Select all the correct answers.
Which two properties are characteristic of lonic compounds?
Answer:
1. Ionic compounds have high melting points.
Ionic compounds have high melting points.2 Ionic compounds are hard and brittle.
Ionic compounds have high melting points.2 Ionic compounds are hard and brittle.3 Ionic compounds dissociate into ions when dissolved in water.
What is the chemical formula for carbon tetrafluoride?
The Periodic Table
1
mono-
2
di-
3
4
tetra-
5
penta-
hexa-
6
7
hepta-
8
Oct-
9
nano-
10
deca-
What is the actual specific heat capacity of the silver in the Calorimetry Lab?
0.234 J/gK
0.133 J/gK
0.035 J/gK
0.023 J/gK
The actual specific heat capacity of the silver in the Calorimetry Lab is given as 0.234 J/gK.
What is specific heat capacity?
Specific heat capacity is the amount of heat required to raise a unit mass of a substance by 1 degree kelvin.
The specific heat capacity of silver or amount of heat required to raise a unit mass of silver metal is 0.234 J/gK.
Thus, the actual specific heat capacity of the silver in the Calorimetry Lab is given as 0.234 J/gK.
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HELP PLEASE 15 POINTS
The rate law for a reaction is found to be rate = k[X]4. By what factor does the rate increase if [X] is doubled?
Which statement best describes what happens as thermal energy from the
sun warms the pavement?
A. The thermal energy absorbed by the pavement is destroyed.
B. The thermal energy that is not absorbed by the pavement is
destroyed.
C. Some thermal energy is absorbed by the pavement, and some is
destroyed.
D. The thermal energy of the sun is transferred to the pavement.
Answer:
D
Explanation:
The correct answer would be that the thermal energy of the sun is transferred to the pavement.
Thermal energy refers to the internal energy possessed by a system by virtue of the movement of molecules within such a system. In other words, it is the heat energy possessed by a system.
When the thermal energy from the sun warms the pavement, it means that the thermal energy from the sun has been successfully transferred to the pavement. Thermal energy can be transferred by conduction, convection, or by radiation depending on whether the system is a solid, liquid, gas respectively.
The correct option is, therefore, D.
Which of the following describes a limiting reactant? Question 10 options: A) The reactant that runs out last and limits how much product can be made B) The reactant that is present at the smallest mass C) The reactant that runs out first and limits how much product can be made D) An inert element
Answer:
The correct choice is option C) The reactant that runs out first and limits how much product can be made
Explanation:
The limiting reactant is a reactant in a chemical reaction that gets consumed first and thus limits how much product can be formed.
Answer:
The reactant that runs out first and limits how much product can be made
Explanation:
what are the main tybes of mixture
Answer:
salt and oil
water and salt
water and sugar
Explanation:
What's a third reaction? (Chemistry)
Explanation:
a chemical reaction in which the rate of reaction is proportional to the concentration of each of three reacting molecules
100cm³ of ethane gas diffuses through a porous plug in 100 seconds.What is the molecular mass of the gas Q if 100cm³ of the gas diffuses through the same plug in 121 secknds under the same condition?(C=12.0,H=1.0)
Answer:
The molar mass of gas Q is 43.923 g/mol
Explanation:
The given volume of ethane gas that diffuses through a porous plug in 100 seconds = 100 cm³
Therefore;
The rate of diffusion of ethane gas through the porous plug, [tex]v_{ethane}[/tex], is given as follows;
[tex]v_{ethane}[/tex] = (100 cm³/100 s) = 1 cm³/s
The molar mass of ethane, C₂H₆ = 2×12 g/mol + 6×1 g/mol = 30 g/mol
The given volume of gas, Q, that diffuses through a porous plug in 121 seconds = 100 cm³
∴ The rate of diffusion of the gas, Q, [tex]v_Q[/tex] = 100/121 cm³/s
Graham's Law of diffusion states that the rate of diffusion of a gas is inversely proportional to the square root of the molecular mass of the gas
Mathematically, we have;
[tex]\dfrac{v_A}{v_B} =\sqrt{\dfrac{m_B}{m_A} }[/tex]
Where;
[tex]v_A[/tex] = The rate of diffusion of gas A
[tex]v_B[/tex] = The rate of diffusion of gas B
[tex]m_A[/tex] = The molar mass of the gas A
[tex]m_B[/tex] = The molar mass of the gas B
Therefore, for ethane and gas Q, measured under the same condition, we have;
[tex]\dfrac{v_{ethane}}{v_Q} =\sqrt{\dfrac{m_Q}{m_{ethane}} }[/tex]
[tex]\dfrac{1 \ cm^3/s}{\dfrac{100}{121} \ cm^3/s} =\sqrt{\dfrac{m_Q}{30 \ g/mol} }[/tex]
[tex]m_Q = \left ({\dfrac{121}{100} } \right) ^2 \times 30 \ g/mol = 43.923 \ g/mol[/tex]
The molar mass of gas Q, [tex]m_Q[/tex] = 43.923 g/mol.
The process during which cells of the body harness energy from food consumed by a living organism is ______________________.
57:17
A ball that has a mechanical energy of 65 J has 12 J of kinetic energy. The ball has blank
energy.
J of potential energy
Answer:
53 Joules
Explanation:
Applying the law of conservation of mechanical energy.
Law of conservation of mechanical energy: States that energy although, energy can not be transformed from one form to another, the total energy of the system remain the same.
I.e,
Mechanical Energy = E.K+P.E..................... Equation 1
Where E.K = Kinetic energy, P.E = Potential energy.
From the question,
Given: Mechanical energy = 65 Joules, K.E = 12 J
Substitute these values into equation 1 and solve for P.E
65 = 12+P.E
P.E = 65-12
P.E = 53 Joules
Assertion (A): An orbital cannot have more than two electrons, moreover, if an orbital has two electrons they must have opposite spins.
Reason (R): No two electrons in an atom can have the same set of all the four quantum
numbers.
a) Both A and R are true and R is the correct explanation of A.
b) Both A and R are true but R is not the correct explanation of A.
c) A is true but R is false.
d) Both A and R are false.
pls answer
Answer:
the correct answer is option ( A )
Both A and R are true and R is the correct explanation of A.
Explanation:
hope it helps you
Mark my answer as brainlist
have a nice day
hurry
A solution:
A. is a mixture that is made when a solid dissolves and combines with a liquid.
B. is the amount of a substance that will combine with another substance before they begin to chemically combine.
C. is the amount of a substance that will dissolve in 1 dm3 of water at 25 C .
D. is two or more substances that are combined together but not chemically joined.
Reset Selection
Answer:
b is the correct answer ok
A solution is made up of solute and solvent. It is an addition of two or more substances to each other that combines physically and chemically. Thus, option B is correct.
What is a solution?A solution is the mixture of solutes that can be more than one in a solvent that has the same composition all over (homogenous). A solution comprises two main elements called a solute and a solvent.
A solute is the part of the solution that has been added to the solvent for desolvation. On the other hand, the solvent is the substance that dissolves the solute in them to make a solution.
The homogenous mixture or the solution can be created by mixing salt and water, sugar and water, mercury in amalgamated zinc, coffee, vinegar, etc.
Therefore, option B. a solution is the addition of the substances that combine physically.
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Is there any Chemical including in BIOGESIC?
Can you tell me if it was included?
Answer:
This combination product contains 2 medications, acetaminophen and an antihistamine. Acetaminophen helps to reduce fever and/or mild to moderate pain (such as headache, backache, aches/pains due to muscle strain, cold, or flu).
Explanation:
it will help you. may be
Answer:
looooser
mark me brailist
What is the aim of cleaning of the iron nails before doing the experiment?
que chest pain
These may be signs of a serious condition. See your doctor
Ask a doctor before use if you have:
had heartburn over 3 months. This may be a sign of a more serious condition.
sfregent wheezina, particularly with heartbum
unexplained weight loss
Bea or vomiting
stomach pain
Ask a doctor or pharmacist before use if you are taking a prescription drug Acid reducers
may utteract with certain prescription drugs.
Stop use and ask a doctor it:
your heartburn continues or worsens
you need to take this product for more than 14 days
you need to take more than 1 course of treatment every 4 months
w you got diarrhea
you develop a rash or joint pain
I pregnant or breast-teeding, ask a health professional before uso.
Koop out of reach of children. In case of overdose, get medical help or contact a Poison
Control Center night away (1-800-222-1222).
Answer:
.........................okay?
Sodium is dissolved under kerosene oil or paroffin to protect it from the air. 3) State. Huckle's rule for aromaticity with example. How does benzene react with Chlorine in presense of Sun light
Answer:
His rule states that if a cyclic, planar molecule has 4n+2 π electrons
What is the order, plz answer
Answer:
C A B
Explanation:
come on, you also know this from normal water waves.
which ones are stronger (= have more energy) ? the small ones or the big ones ?
and the same applies to all waves. the bigger the waves (higher amplitude), the more energy.
How many grams of solute is there in 250 mL of a 0.10M CaCl2 solution ?
Answer:
2.775 g
Explanation:
Given that;
Number of moles = concentration × volume
Concentration = 0.10M
Volume =250 mL
Number of moles = 250/1000 × 0.10
Number of moles = 0.025 moles
Also;
Number of moles = mass/molar mass
Molar mass of CaCl2= 111 g/mol
Mass = Number of moles × molar mass
Mass = 0.025 moles × 111 g/mol
Mass= 2.775 g
