Answer:
Louis braille was a french educator and inventor of a sytem of reading and writing for use use by the blind or visually impaired . his system remains virtually unchanged to this day and is know worldwide simply as braille
9. What metric unit would be most
appropriate to use when measuring
the length of a paperclip?
a. Millimeter
b. Decimeter
c. Meter
d. Kilometer
Answer: a. Millimeter
Explanation:
A paperclip is a small device or instrument that can be used to hold the papers or stack of papers together. The length of the paperclip can be measured using millimeter. It is equal to the thousands of meters. The millimeter is a dimension which is used to measure the very small length objects which have visible scale distances and length.
Decimeter can be used to measure the length of the object smaller than paperclips. Meter and kilometers are used for objects and distances larger than paperclip.
Isopropanol burns in oxygen to yield carbon dioxide, water, and heat. Which word equation best represents this chemical reaction?
isopropanol Right arrow. carbon dioxide + water + heat
isopropanol Right arrow. carbon dioxide + water + oxygen
isopropanol + oxygen Right arrow. carbon dioxide + water + heat
isopropanol + oxygen + heat Right arrow. carbon dioxide + water
Answer:
isopropanol + oxygen Right arrow. carbon dioxide + water + heat
Explanation:
Word equation:
isopropanol + oxygen → carbon dioxide + water + heat
Chemical equation:
2C₃H₇OH + 9O₂ → 6CO₂ + 8H₂O + Heat
The given reaction is combustion of isopropanol. Isopropanol burn in the presence of oxygen and produced carbon dioxide and water. Heat is also produced in this reaction.
The given reaction also follow the law of conservation of mass. There are equal number of moles of each element on both side of reaction equation thus mass remain conserved.
isopropanol + oxygen Right arrow. carbon dioxide + water + heat
The following information should be considered:
Word equation:
isopropanol + oxygen → carbon dioxide + water + heat
Chemical equation:
[tex]2C_3H_7OH + 9O_2 \rightarrow 6CO_2 + 8H_2O + Heat[/tex]
The given reaction is combustion of isopropanol. Isopropanol should be burn with the presence of oxygen and generated carbon dioxide and water. Heat is also generated in this reaction. The given reaction also follows the law of conservation of mass
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Many organisms on Earth exhibit similar ____________.
Question 1 options:
time
single-celled
characteristics
nonliving
Answer:
characteristics
Explanation:
i promise becasue i am a teacher so i hope you like it
Which of the following would likely occur as a result of an oil spill in the ocean?
I. The levels of salt and other nutrients typically present in ocean water would greatly increase.
II. There would be no more upwelling of nutrients from cold ocean depths.
III. Humans would be less able to use fish and shellfish from the affected area as food.
IV. There would be global interruptions in the water cycle.
A. III only
B. IV only
C. I and III only
D. I, II, III, and IV
Answer:
D.
Explanation:
The Oil spill effects on environments and habitats can be catastrophic: they can kill plants and animals, disturb salinity/pH levels, pollute air/water and more. Read more about the types of oil pollution.
Statements that express occurrences as a result of oil spill in the ocean are:
C: I. The levels of salt and other nutrients typically present in ocean water would greatly increase.
III. Humans would be less able to use fish and shellfish from the affected area as food.
An oil spill can be regarded as a of release liquid petroleum hydrocarbon into the environment.This release can be on land or in the body of water especially ocean, however this spillage is very dangerous to aquatic lives which indirectly affects man.Once spillage occur, levels of salt and other nutrients will increase in the ocean and this can harm aquatic lives.especially the marine ecosystem, due to human activity, and is a form of pollution.
Therefore option C is correct.
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A 50.0mL flask filled with a solution of hydrogen peroxide has a total mass of 88.5 g. The mass of the flask is 16.5 g. The density of the hydrogen peroxide solution is
Answer:
1.44 g/mL
Explanation:
total mass is mass of the flask plus mass of the solution
TM = Flask + H2O2
88.5 = 16.5 + x
x = 72.0 gram
density = mass/volume
H2O2 density = 72/50
= 1.44 g/mL
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Think critically, explain why some fronts produce stronger storms than others. GIVE 2 EVIDENCES PLSSS.
I WILL GIVE YOU BRAINLIEST
Propionic acid (CH3CH-COOH) has a K, 1.3 x 10^-5 and phosphoric acid (H3PO2) has a Ka = 7.5 x 10^-3
Choose the conjugate base for each.
A. CH3CH2COO2- for CH3CH2COOH; HPO4 2- for H3PO4
B. CH3CH2CO- for CH3CH2COOH; H2PO3 - for H3PO4
C. CH3CH2COOH2 for CH3CH2COOH; H4PO4 for H3PO4
D. CH3CH2COO- for CH3CH2COOH; H2PO4 - for H3PO4
Answer:
D. CH3CH2COO- for CH3CH2COOH; H2PO4 - for H3PO4.
Explanation:
Hello!
In this case, since the ionization of a weak acid produces a conjugate acid, molecule to which the leaving H⁺ is added to, and a conjugate base, everything that remains after the withdrawal of the H⁺, we can note down the ionization of each acid down below:
[tex]CH_3CH_2COOH\rightleftharpoons CH_3CH_2COO^-+H^+\\\\H_3PO_4\rightleftharpoons H^++H_2PO_4^-[/tex]
Thus, we notice that the answer is D. CH3CH2COO- for CH3CH2COOH; H2PO4 - for H3PO4 because the phosphoric acid is most likely to ionize to dihydrogen phosphate ions rather than phosphate, or hydrogen phosphate ions it undergoes a stepwise ionization in which the first step is the predominant one.
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Which chemical equation is unbalanced?
C + O2 Right arrow. CO2
Sr + O2 Right arrow. 2SrO
6H2 + 3O2 Right arrow. 6H2O
H2 + H2 + O2 Right arrow. H2O + H2O
Answer:
Sr + 02 Right arrow.2Sr0
Answer:
b
Explanation:
Decide whether the compound is ionic or molecular, if you can.
A Compound is a deep red solid with a noticeable unpleasant smell. It dissolves slightly in water, and a solution of in of water doesn't change the electrical conductivity of the water.
Answer:
Molecular solid
Explanation:
A molecular solid has a low melting point, they are soft and do not conduct electricity.
We have been told in the question that the solid does not really dissolve in water and it's solution does not improve the electrical conductivity of water. Hence, it must be a molecular solid.
anybody?i will appreciate it
Answer:
fat provide 9 calories per gram
While in Europe, if you drive 123 km day, much you spend on gas in one week it gas costs 1.10 euros per liter and your car's gas mileage is 27.0mi / g * a * l ? Assume that 1 euro = 1.26 dollars.
Money spend = $103.86
Further explanationGiven
Distance :123 km/day
cost 1.1 euros/L
your car's gas mileage is 27.0mi / gal
Required
Money needed
Solution
Distance/week : 123 x 7 = 861 km/week
1 km = 0.621 miles, so for 861 km =
861 x 0.621 = 534.68 miles/week
Amount of gas : 534.68 miles : 27 miles/gal = 19.8 gal
1 gal = 3.785 L , so 19.8 gal =
19.8 x 3.785 = 74.94 L
Cost for euros = 74.94 x 1.1 = 82.43
Cost for dollars = 82.43 x 1.26 = $103.86
Science Safety Poster Project
Why do balls bounce higher on hard floors than on carpet?
a) They don't. That is a myth.
b) The carpet friction creates thermal energy.
c) The carpet fibers attract the molecules in the ball.
d)The carpet is so nice and soft the ball doesn't want to go.
Answer:
I'm pretty sure c......
Answer is B
The friction causes the ball to lose energy on carpets, which makes the ball bounce less. On hard floors, not as much thermal energy is lost, which is why it bounces higher.
Imagine an alternate universe where the value of the Planck constant is 6.6207 x 10^-36 J*s.
In that universe, which of the following objects would require quantum mechanics to describe, that is, would show both particle and wave properties? Which objects would act like everyday objects, and be adequately described by classical mechanics?
1. A buckyball with a mass of 1.2 x 10-21 g, 0.7 nm wide, moving at 38. m/s.
classical or quantum?
Answer:
See explanation
Explanation:
According to Louis de Broglie, matter has an associated wavelength. He was the first scientist to establish the idea of wave-particle duality or wave- particle paradox.
The display of wavelike properties by objects in the universe is dependent on the magnitude of the of the mass of the body. Small objects have a large associated wavelength and can be described completely by quantum mechanics.
A buckyball with a mass of 1.2 x 10-21 g, 0.7 nm wide, moving at 38. m/s has a very small mass and significant associated wavelength hence the system can be completely described by quantum mechanics.
Marine chemist exam in the mass percent composition of manganese sulfide compound from ocean floor he determined that 60.2% of this compound is sulfur determine the mole ratio between manganese and sulfur
Explanation:
Let the mass of the compound be 100g.
There are 60.2g of sulfur.
Moles of sulfur
= 60.2g / (32.07g/mol) = 1.877mol
There are 100g - 60.2g
= 39.8g of manganese.
Moles of manganese
= 39.8g / (54.94g/mol) = 0.724mol
Mole ratio of manganese to sulfur
= 0.724mol : 1.877mol = 1 : 2.5.
name all nonmetals that are noble has.
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How do I arrange greatest to least magnitude according to absolute value? What does that mean?
-2.58 x 10^6
-4.18 x 10^-2
-5.29 x 10^-5
Answer:
[tex]-2.58\times 10^6[/tex]
[tex]-4.18\times 10^{-2}[/tex]
[tex]-5.29\times 10^{-5}[/tex]
Explanation:
The absolute value of a number is the value of the number without the sign. So, the absolute value of [tex]-1[/tex] is [tex]1[/tex] and [tex]1[/tex] is also [tex]1[/tex].
It is generally denoted in the following way [tex]|-1|=1[/tex]
Here the numbers are
[tex]|-2.58\times 10^6|=|-2580000|=2580000[/tex]
[tex]|-4.18\times 10^{-2}|=|-0.0418|=0.0418[/tex]
[tex]|-5.29\times 10^{-5}|=|-0.0000529|=0.0000529[/tex]
So, the order of the numbers from greatest to the least is
[tex]-2.58\times 10^6[/tex]
[tex]-4.18\times 10^{-2}[/tex]
[tex]-5.29\times 10^{-5}[/tex]
Read the descriptions below of two substances and an experiment on each. Decide whether the result of the experiment tells you the substance is a pure substance or a mixture, if you can .
Sample A is 100.mL of a clear liquid. The density of the liquid is measured, and turns out to be 0.77/gmL. The liquid is then heated in a flask until it boils. The vapor that rises off the boiling liquid is collected for 10 minutes and cooled until it condenses into a separate beaker. The density of the liquid that remains in the flask is then measured, and turns out to be 1.04/gmL.
Sample B is 100.g of a coarse grey powder with a faint unpleasant smell. 15.g of the powder are dissolved in ethanol. 0.5mg of the resulting black solution is carefully dropped onto a thick sheet of paper laid flat in a tray. After 30 minutes the initial round black stain has spread out and faded in color to a deep purple. Additionally, there is a dark green ring surrounding the inner stain.
a. Is sample A made from a pure substance or a mixture?
b. If the description of the substance and the outcome of the experiment isn't enough to decide, choose "can't decide.
c. Is sample B made from a pure substance or a mixture?
d. If the description Of the substance and the outcome of the experiment isn't enough to decide, Choose "can't decide.
Answer:
Samples A and B are mixtures
Explanation:
For sample A, we were told that the initial density of the solution is 0.77/gmL. After distillation, the liquid left has a density of 1.04/gmL. Apparently, A is a mixture of liquids.
As for sample B, the spread of the chromatogram resulting in different colours show that the sample B is not pure. It is a mixture of substances. A pure sample will yield only a single spot.
Can I get Help with this question ♂️ please?
Answer:
Molar mass of the substance
What is the correct name of CUCIO2
Chemistry
Answer:
Copper(II) Chlorite = Cu(ClO2)
Explanation:
how you write the compound is very important as well
When recommending solutions to decrease human impact, which location were you able to make the greatest positive impact? Please explain your selection by using data from the simulation.
What recommendations would you give to your local community to help to decrease the local effects of human impact on the environment? List 2 recommendations and how they will positively impact your community.
What recommendations would you give to the global governments to help decrease the global effects of human impact on the environment? List 2 recommendations and how they will positively impact our planet.
When recommending solutions to decrease human impact, which location were you able to make the greatest positive impact? Please explain your selection by using data from the simulation.
New york, 893 - 853 = 40 which is the highest quotient.
What recommendations would you give to your local community to help to decrease the local effects of human impact on the environment? List 2 recommendations and how they will positively impact your community.
Installing solar panels and replanting 2 trees for every tree that’s been cut down, this will help the atmosphere and deforestation.
What recommendations would you give to the global governments to help decrease the global effects of human impact on the environment? List 2 recommendations and how they will positively impact our planet.
Constructing using only recycled materials decreases water pollution to 823 ppm and Creating more protected areas decreases air pollution to 368 ppm this will help the environment and oxygen.
Answer:
........
Explanation:
The following is a procedure that was theoretically performed by a student. Read through the procedure and answer the questions below.1.A 10.0 mL graduated cylinder to measure 10.0 mL of a 1.00 M CaCl2 solution into an initially empty 50.0 mL beaker.2.A 50.0 mL graduated cylinder was then used to measure out 25.0 mL of 0.500 M K2CO3. This K2CO3solution was then added to the beaker containing the CaCl2 solution. The solution became cloudy, and the student concluded that a precipitate must have formed. Write a balanced chemical reaction below, including phases, and identify the chemical formula of the precipitate:
Answer:
CaCl2 (aq) + K2CO3(aq) ---------> CaCO3(s) + 2KCl(aq)
Explanation:
We have the reactants as calcium chloride and potassium carbonate. Recall that we are expecting that the reaction will yield a precipitate. We must keep that in mind as we seek to write its balanced chemical reaction equation.
So we now have;
CaCl2 (aq) + K2CO3(aq) ---------> CaCO3(s) + 2KCl(aq)
Recall that the rule of balancing chemical reaction equation states that the number of atoms of each element on the right side of the reaction equation must be the same as the number of atoms of the same element on the left hand side of the reaction equation.
RESEARCHING ENERGY TRANSFORMATIONS
Choose 2 types of technology and describe the energy transformation that occurs within those types of technology
that make them work. Discuss the processes in one paragraph for each. Choose from the following: Drones, cell
phones, laptops, iPads, cars, television, gaming system, cameras, microwaves or choose your own!
of technology here
This is not
Answer:
Two types of technology and the energy transformation that occurs within those types of technology that make them work is described below in detail.
Explanation:
A drone, in technological courses, is an unmanned aircraft. ... Typically, a drone is a hovering automaton that can be remotely commanded or cruise autonomously through software-managed flight systems in their installed systems, working in combination with onboard sensors and GPS.
Laptops consolidate all the input/output parts and abilities of a desktop processor, including the presentation screen, tiny speakers, a keyboard, a data storehouse device, sometimes an optical disc drive, aiming devices, with a running system, a processor, and memory into a particular unit.
A gas in a sealed container has a pressure of 100 kPa at a temperature of 27 C. If the pressure in the container is increased to 20 kPa, what is the new temperature?
Answer: 32.4 C
Explanation: Gay-Lussac's Law or Third Gas Law states that for a constant volume, the pressure is directly proportional to absolute temperature: P alpha T; also stated as P/T = K, where K is a constant, and similarly, P1/T1 = P2/T2 .
Here P1= 100 kPa, P2=120 kPa (If pressure increases by 20 kPA), T1=27 C [Given]
Hence, T2= (T1*P2)/P1 = (27*120)/100=32.4 C [C is degree in Celcius]
The new temperature of the gas in the container when the pressure increased by 20 KPa is 87 °C
Data obtained from the question Initial pressure (P₁) = 100 KPa Initial temperature (T₁) = 27 °C = 27 + 273 = 300 KNew pressure (P₂) = 120 KPa New temperature (T₂) =? How to determine the new temperatureThe new temperature of the gas can be obtained as follow:
P₁ / T₁ = P₂ / T₂
100 / 300 = 120 / T₂
Cross multiply
100 × T₂ = 300 × 120
Divide both side by 100
T₂ = (300 × 120) / 100
T₂ = 360 K
Subtract 273 to obtain answer in °C
T₂ = 360 – 273 K
T₂ = 87 °C
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what is the difference between the number of electrons in an atom of selenium, Se and the number of electrons in an atom of aluminum, Al?
Answer:
Well, electrons can be converted into a atomic number so if SE atomic number is 34 that means it has 34 electrons. AI has a atomic number of 13 meaning it has 13 electrons. So the difference is that SE has more electrons then AI.
PLS HELP GIVING 100 PTS EASY SCIENCE HELP PLS
Answer:
B hope it helps
Explanation:
A coffee cup calorimeter contains 100.0 mL of 1.50 M Ba(NO3)2 at 25.0o C. A student pours 100.0 mL of 1.50 M Na2SO4 at 25.0o C into the calorimeter. A precipitate forms and the temperature rises to 29.7o C. Assume that no heat was lost to the surroundings, the volumes were additive, the specific heat capacity of the solution was 4.184 J/gK, and the density of the solution was 1.00 g/mL.
A. This reaction could be represented as a complete ionic or a net ionic equation. Write the balanced chemical equation that should be used in association with the Delta Hrxn value for this reaction.
B. Find the amount of heat that was lost or gained by the solution in the calorimeter.
C. Find the heat of reaction, Delta Hrxn.
D. Is the reaction endothermic or exothermic?
Answer:
Ba(NO₃)₂ + Na₂SO₄ → BaSO₄ + 2NaNO₃
q = 3.93 kJ
ΔH_{rxn} = 26.2 kJ/mole
Exothermic
Explanation:
Given that:
The Volume of Ba (NO₃)₂ = 100.0 mL
The molarity of Ba (NO₃)₂ = 1.50 M
The volume of Na₂SO₄ = 100.0 mL
The molarity of Na₂SO₄ = 1.50 M
From the above, the total volume of solution = 200.0 mL
Density of solution = 1 g/mL
The balanced equation can be written as:
Ba(NO₃)₂ + Na₂SO₄ → BaSO₄ + 2NaNO₃
We know that:
Density = mass/volume
Thus;
the mass of the solution = density × volume
= 200 × 1
= 200 g
Temperature change ΔT = T₂ - T₁
ΔT = (29.7 - 25)° C
ΔT = 4.7° C
Heat capacity c = 4.184 J/gK
∴
The amount of heat lost or gained q = m× c×ΔT
q = 200 × 4.184 × 4.7
q = 3932.96 J
q = 3.93 kJ
From the above information, we can determine the number of moles of Ba(NO₃)₂ and Na₂SO₄
For Ba(NO₃)₂
number of moles = 0.10 × 1.50
= 0.15
For Na₂SO₄
number of moles = 0.10 × 1.50
= 0.15
∴
ΔH_{rxn} = q/number of moles
ΔH_{rxn} = 3.93/0.15
ΔH_{rxn} = 26.2 kJ/mole
From the reaction, we will notice that the temperature increased. This significantly implies that heat is evolved from the reaction. As such, the reaction is exothermic.
PLEASE HELP WHICH ONE IS IT AND CAN YOU EXPLAN HOW YOU GOT THE ANSWERS TY!!!
In a titration, a 20 mL sample of NaOH(aq) was neutralized by 14.9 mL of 0.13 mol/L
H2SO4(aq). The concentration of the base is
A)8.7 mol/L
B)10.048 mol/L
C)0.19 mol/L
D)0.35 mol/L
/L
Answer:
C)0.19 mol/L .
Explanation:
Hello!
In this case, since the chemical reaction between sodium hydroxide and sulfuric acid is:
[tex]H_2SO_4+2NaOH\rightarrow Na_2SO_4+2H_2O[/tex]
Whereas a 1:2 mole ratio is seen between the acid and the base, we can write:
[tex]2*M_{acid}V_{acid}=M_{base}V_{base}[/tex]
In such a way, we solve for the concentration of base and plug in to obtain:
[tex]M_{base}=\frac{2*M_{acid}V_{acid}}{V_{base}} \\\\M_{base}=\frac{2*0.13mol/L*14.9mL}{20mL} \\\\M_{base}=0.19mol/L[/tex]
Thus, the answer is C)0.19 mol/L
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Question 10 of In which way does a balanced chemical equation demonstrate the conservation of matter? A. It shows the same number of atoms of each element on both sides of the equation. B. It shows how the atoms of an element can appear on only one side of the equation. C. It shows the same number of molecules of each compound on both sides of the equation. D. It shows how matter can be both created and destroyed by a chemical reaction. SJEMALT
Answer:
it’s probably c
Explanation:
Answer:
C
Explanation:
I searched it up
How do I round 74,000 to have only one significant figure?
Answer:
7x10⁴.
Explanation:
Hello!
In this case, when rounding big number to a representation with less significant figures than it, we need to make sure we remove the spare figures and round up whether the next digit is five or more.
In such a way, for 74,000, we notice that 4 is not enough to round up the 7, that is why the number would contain a 7 only; moreover, to get rid of the thousand places, we need to introduce an exponent in 4 places, which means that the result would be:
7x10⁴.
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