Speed is defined as the distance travelled per unit time. Mathematically, it is expressed as:
[tex]Speed = \frac{Distance }{Time}[/tex]
To solve the question given above, we'll begin by converting 23.6 miles per hour to metre per second (m/s). This can be obtained as follow:
1 mph = 0.447 m/s
Therefore,
23.6 mph = 23.6 × 0.447
23.6 mph = 10.5492 m/s
Thus, 23.6 mph is equivalent to 10.5492 m/s
Finally, we shall determine the time taken for the racer to travel 20 m. This can be obtained as follow:
Speed = 10.5492 m/s
Distance = 20 m
Time =?[tex]Speed = \frac{Distance }{Time } \\\\10.5492 = \frac{20}{Time}[/tex]
Cross multiply
10.5492 × time = 20
Divide both side by 10.5492
[tex]Time = \frac{20}{10.5492 } \\[/tex]
Time = 1.9 sTherefore, it will take 1.9 s for the racer to travel a distance of 20 m.
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Calculate the number of moles for 50.7 g of hydrogen gas
Answer: 50.7 moles
Explanation:
given mass/ molecular mass
= 50.7/1
=50.7
Answer:
[tex]\boxed {\boxed {\sf 25.1 \ mol \ H_2}}[/tex]
Explanation:
We are asked to calculate the number of moles in 50.7 grams of hydrogen gas. To do this, we will use the molar mass or the mass of 1 mole of a substance. These values are found on the Periodic Table because they are equivalent to the atomic masses, but the units are grams per mole instead of atomic mass units.
Look up the molar mass of hydrogen (H).
H: 1.008 g/molNote that we are given grams of hydrogen gas. This is a diatomic molecule with 2 hydrogen atoms. The formula is H₂. Multiply the molar mass by 2 to find hydrogen gas's molar mass.
H₂ = 1.008 *2 = 2.016 g/molNow we can convert using dimensional analysis. Set up a ratio using the molar mass.
[tex]\frac {2.016 \ g \ H_2}{1 \ mol \ H_2}[/tex]
We are converting 50.7 grams to moles, so we multiply the ratio by this value.
[tex]50.7 \ g \ H_2 *\frac {2.016 \ g \ H_2}{1 \ mol \ H_2}[/tex]
Flip the ratio so the units of grams of hydrogen gas cancel.
[tex]50.7 \ g \ H_2 *\frac{1 \ mol \ H_2} {2.016 \ g \ H_2}[/tex]
[tex]50.7 \ *\frac{1 \ mol \ H_2} {2.016 }[/tex]
[tex]\frac {50.7} {2.016 } \ mol \ H_2[/tex]
[tex]25.14880952 \ mol \ H_2[/tex]
The original value of grams (50.7) has 3 significant figures, so our answer must have the same. For the number we calculated, that is the tenths place. The 4 in the hundredth place to the right tells us to leave the 1 in the tenths place.
[tex]25.1 \ mol \ H_2[/tex]
50.7 grams of hydrogen gas is equal to approximately 25.1 moles of hydrogen gas.
True or false
an astronomer studies the universe beyond Earth.
Answer:
More generally, astronomy studies everything that originates beyond Earth's atmosphere. Cosmology is a branch of astronomy that studies the universe as a whole. Astronomy is one of the oldest natural sciences. The early civilizations in recorded history made methodical observations of the night sky.
Question
"Drag each tile to the correct location on the concept map", for the question.
Read the instructions for this self-checked activity. Respond to each question, and check your answers. At the end of the activity, write a brief
evaluation of your work.
Answer:
i hope this helps, also you might want to put it into your own words because this was directly from the answer key :)
Explanation:
Faustus Faustus is the protagonist of the play. He is a brilliant scholar who makes a deal with Lucifer to exchange his soul for magical power. He later regrets his decision, but it’s too late and his soul is carried away to hell.
Mephastophilis Mephastophilis is a demon that Faustus calls upon to help him with magic. He turns into Faustus's servant in his pact with the devil.
Valdes and Cornelius Valdes and Cornelius are friends of Faustus who teach him the art of black magic.
three scholars The three scholars are friends of Faustus who are concerned about his welfare.
Lucifer Lucifer (the devil) is Mephastophilis’s master. He makes a deal with Faustus.
Wagner Wagner is Faustus’s servant. He learns how to work magic from his master’s books.
clown The clown becomes Wagner's servant. He provides comic relief in the story.
good angel The good angel is a spirit that tries to get Faustus to repent.
evil angel The evil angel is a spirit that tempts Faustus to rebel against God and make a pact with the devil.
the pope The pope is the head of the Roman Catholic Church and symbolizes the religious beliefs that Faustus has abandoned.
horse-courser The horse-courser is a horse trader who purchases a horse from Faustus.
old man The old man is a mysterious figure who takes the place of the good and evil angels in the last scene of the play.
Explain why arginine is a basic amino acid
Answer:
There are three amino acids that have basic side chains at neutral pH. These are arginine (Arg), lysine (Lys), and histidine (His). Their side chains contain nitrogen and resemble ammonia, which is a base. Their pKa's are high enough that they tend to bind protons, gaining a positive charge in the process.
Hope it helps you.Answer :
arginine is basic amino acid because it's side chain group contains a full positive charge at the physiological pH. Histidine is also considered basic but it can have a positive or a neutral charge on its side chain group at the physiological pH
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Evidence for the Big Bang Theory
Group of answer choices
The amount of Lead and Iron in the Universe
Discovery of the Cosmic Background Radiation
Stars are like fires from the explosion
Answer:
2nd one
Explanation:
Big bang echo other ones make no sense.
Take a look at your rubbing alcohol at home. What is its main composition?
Answer:
It is a mixture of denatured alcohol, water, and agents added to make the alcohol unpalatable to drink.
Density is defined as the mass of a substance divided by its volume, or D=M/V. Calculate the
volume of 119.9 grams of a substance that has a density of 0.8 g/mL
Answer: 149.9 ml
Explanation: Do as the formula suggests: D = M/V
0.8 g/ml = 119.9 grams/V
V = (119.9 grams)/(0.8 grams/ml) = 212.8 ml
Note how the grams cancel and the ml moves to the top.
Which among the following represents a set of isotopes? Atomic nuclei containing:
a) 20 protons and 20 neutrons
b) 21 protons and 19 neutrons
c) 22 neutrons and 18 protons
d) 20 protons and 22 neutrons
e) 21 protons and 20 neutrons
Answer:
d. 20 protons and 22 neutrons
Atomic nuclei containing 20 protons and 22 neutrons. Thus, option D is correct.
What is an electron?
An electron is defined as a subatomic particle which is charged negatively either bound to an atom or not it means free. The nucleus of an atom is made up of electron, proton and neutron. The electron is a basic particle and electron is not made of anything.
The nature of electron is free it means they are present freely in nature and consist of an atom.The main function of electron is that they play the role of negatively- charged component of an atom.
The electrons are primary source of current conducting and electrons number as well as atomic number of an element is always same or equal. There is no size of electron but the mass of electron is 9×10^-31.
Therefore, Atomic nuclei containing 20 protons and 22 neutrons. Thus, option D is correct.
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Where are the metals located on the periodic table? the nonmetals?
Answer:
The metals are located on the left and the non-metals are located on the right.
Explanation:
Hope this helps :)
what is chemical change ?
[tex]\huge{ \color{violet}{ \boxed{ \color{hotpink}{Answer}}}}[/tex]
➣ Chemical ChangeIt occurs when new materials are formed by a change in the way the atoms are bonded together.Heat, light or electrical energy is often emmitted or absorbed.[tex] \: [/tex]
[tex]\large\tt\:⚘ \: MishiChaeYoon \: ⚘[/tex]
If I have a bottle of compound X at a pressure of 45 atm and temperature of 100 °C, what will happen if I raise the temperature to 400 °C?*
Answer:
55/350
Explanation:
because the answer is in the middle of 50and 400
4) A sample of sodium bromide, NaBr, has a mass percentage of sodium of 22.34%.
a) If the sample of sodium bromide were contaminated with sodium chloride, NaCl, would the mass percentage of Na in the sample be higher or lower than the pure sample? Justify your claim.
b) If the sample of sodium bromide were contaminated with sodium iodide, NaI, would the mass percentage of Na in the sample be higher or lower than the pure sample? Justify your claim
Explanation:
The trick here is to realize the every sample of sodium bromide, regardless of its mass, will contain
22.34
%
sodium by mass.
This is true because sodium and bromide always combine in definite proportions, i.e. stable ratios by mass, to form sodium bromide.
Now, a
22.34
%
percent concentration by mass means that every
100 g
of sodium bromide will contain
22.34 g
of sodium and
100 g
−
22.34 g
=
77.66 g Br
Therefore, you can say that the mass ratio that exists between sodium and bromine in any sample of sodium bromide will be
22.34 g Na
77.66 g Br
=
22.34
77.66
You can thus use this definite proportion to say that a
5.69 g
sample of sodium bromide will contain
5.69
g NaBr
⋅
22.34 g Na
100
g NaBr
=
1.271 g Na
=
¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯
∣
∣
a
a
1.27 g Na
a
a
∣
∣
−−−−−−−−−−−−−
The answer is rounded to three sig figs.
You can use the known definite proportion to find the mass of bromide present in the sample
1.271
g NaBr
⋅
77.66 g Br
22.34
g NaBr
=
4.42 g Br
This checks out because
mass of NaBr sample
5.69 g
−
mass of Na
1.27 g
=
mass of Br
4.42 g
The answers to your questions are ;
a) The mass percentage of Na in the sample will be higher in the sample
b) The mass percentage of Na in the sample will be be lower in the sample
Given that:
Mass percentage of sodium contained in sodium Bromide = 22.34%
a) Determine if the mass percentage of Na will be higher or lower when sodium Bromide is contaminated with sodium chloride
mass percentage of Na in sodium bromide
= ( mass of Na / mass of NaBr )*100
The mass of sodium in NaBr and NaCl is the same while the mass of Br is not same ( greater than ) as the mass of Cl. hence when NaBr is contaminated with NaCl the total mass of in percentage NaBr will decrease. and This decrease in mass of NaBr will lead to a decrease/lower mass percentage of Na in the sample
b) When NaBr is contaminated with NaI
The mass of Na is the same in NaBr and NaI while the mass of I is not the same ( greater than ) as the mass of Br, therefore the total mass will increase and the increase in the Total mass in percentage will lead to an increase/higher value of Na in the given sample.
hence the mass percentage of Na will decrease when NaBr is contaminated with NaCl while the mass percentage of Na will increase when NaBr is contaminated with NaI
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1°C rise in temperature is equal to a rise of
Answer:
1°C rise in temperature is equal to a rise of 59°F
Answer:
Hence 1℃ rise in temperature is equal to the rise in 59℉.
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what type of orbital is occupied by an electron with the quantum numbers n=3, 1=2? How many degenerate orbital's of this type are found in a multi electron atom
The orbital is occupied by an electron with the quantum numbers n=3, l=2 will be 3d where n is orbit and l is band the d orbital have 5 degenerate orbitals.
What are orbit and orbitals?Orbitals are the well defined circular paths into which electron revolve around the nucleus in 2D mostly denoted by K L M N etc and all of them will be circular in the shape and non directional as well.
Orbitals are the 3D space of the nucleus where the probability of finding the electron will always be greater or maximum denoted by s p d and f and having shapes like s orbital is spherical shaped p orbital is in some other shape.
Therefore, orbital is occupied by an electron with the quantum numbers n=3, l=2 will be 3d where n is orbit and l is orbital and the d orbital have 5 degenerate orbital's.
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Calculate with correct number of significant figures: 685.90 + 152.1 - 0.125
Answer:
837.9
Explanation:
draw a diagram to show what happened to the particle, when a liquid cools to a solid?
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An certain element Y has two naturally occurring isotopes, 6Y (isotopic mass = 6.015123 amu) and 7Y (isotopic mass = 7.016005 amu). If the atomic mass of the element is 6.9412 amu. What is the percent abundance of 6Y?
Do not include the symbol "%" in your answer.
Report the correct answer to three significant figures
The percentage abundance of 6Y is 0.102.
An Isotope refers to two or more atoms that has the same atomic number but different mass numbers.
We have been informed from the question that the atomic mass of the element is 6.9412 amu.
Let the abundance of isotope 6Y be x
Let the abundance of isotope 7Y be 1-x
Hence;
6.9412 = 6.015123x + 7.016005(1 - x)
6.9412 = 6.015123x + 7.016005 - 7.016005x
6.9412 - 7.016005 = 6.015123x - 7.016005x
-0.102 = -1x
x = -0.102/-1
x = 0.102
Hence the percentage abundance of isotope 6Y is 0.102.
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The percentage abundance of 6Y is 7.47%
Isotopy is the phenomenon whereby two or element have the same atomic number but different mass number due to the difference in their neutron number.
We'll begin the solving as follow:
Let A represent isotope 6Y
Let B represent isotope 7Y
From the question given above, the following data were obtained:
For isotope A (6Y):Mass of A = 6.015123 amu
Abundance of A (A₀) =…? For isotope B (7Y):Mass of B = 7.016005 amu
Abundance of B (B₀) = (100 – A₀%
Relative Atomic mass of Y = 6.9412 amu
The abundance of 6Y can be obtained as follow:
[tex]RAM = \frac{MassA * A_{0} }{100} + \frac{MassB * B_{0} }{100}\\\\6.9412 = \frac{6.015123 * A_{0}}{100} + \frac{7.016005 (100 - A_{0})}{100}\\\\6.9412 = 0.06015123 A_{0} + \frac{701.6005 - 7.016005A_{0}}{100}\\\\6.9412 = 0.06015123 A_{0} + 7.016005 - 0.07016005A_{0}[/tex]
Collect like terms
[tex]6.9412 - 7.016005 = 0.06015123A_{0} - 0.07016005A_{0}\\-0.074805 = -0.01000882A_{0}[/tex]
Divide both side by –0.0100882
[tex]A_{0} = \frac{-0.074805}{-0.01000882}\\\\[/tex]
A% = 7.47%Therefore, the abundance of 6Y is 7.47%
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Which of the following can be referred to as a d7 ion? * O Cu4+ o Mn 4+ O O O Ni4+ O None of the above .
Transition metals are known to have incompletely filled d- orbitals. For this reason, they are commonly referred to as the d- block. Cu4+ is a d7 ion.
An ion is formed when electrons are lost from or gained in a neutral atom.
An ion is a positively or negatively charged chemical specie. Chemical species form ions by loss or gain of electrons.
An atom is neutral if it has equal number of protons and electrons. When an atom has lost electrons, it forms a positive ion.
Copper has electronic configuration; 1s2 2s2 2p6 3s2 3p6 4s2 3d9. When four electrons are lost, its electronic configuration now becomes;
1s2 2s2 2p6 3s2 3p6 3d7.
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Please solve these two QUESTION .
its my ASSIGNMENT
Explanation:
It is the total mass of protons and neutrons in an individual atom or isotope. Since, Atomic Mass is total mass of protons and neutrons in an individual atom or isotope and not the actual weight of an Atom.
this means that it exists in the form of isotopes and is generally in fraction.
Which methods separate a mixture according to the size of the particles?
A. distillation and evaporation
B. filtration and chromatography
C. filtration and evaporation
D. distillation and chromatography
Answer:
Only one of these methods separates compontents based on size.
The answer is filiration and chromatography.
Explanation:
Anyone to help me solve this question. Am going to give brainliest
why does copper Cu (I) have a short lifespan
Answer:
Copper (Cu), chemical element, a reddish, extremely ductile metal of Group 11 (Ib) of the periodic table that is an unusually good conductor of electricity and heat. Copper is found in the free metallic state in nature.
Explanation:
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A graduated cylinder is filled with 20ml of water. A rock is dropped in to the graduated cyclinder and the volume of water rises to 30ml
inside the graduated cylinder. The mass of the rock is 23g. What is the density of the rock?
2.3g/ml
0.77g/ml
5g/ml
1.15g/ml
Answer:
[tex]\boxed {\boxed {\sf 2.3 \ g/mL}}[/tex]
Explanation:
We are asked to find the density of a rock. Density is the substance's mass per unit volume. The formula for calculating density is:
[tex]\rho= \frac{m}{v}[/tex]
The mass of the rock is 23 grams. The volume was found using water displacement. A known amount of water was measured, the rock was added to the graduated cylinder, and the water level was recorded again. The volume is the difference between the final and initial water level. The graduated cylinder originally had 20 milliliters and the water rose to 30 milliliters.
volume = final water level - initial water level volume = 30 mL - 20 mLvolume = 10 mLNow we know the mass and the volume.
m= 23 g v= 10 mLSubstitute the values into the formula.
[tex]\rho= \frac{ 23 \ g }{30 \ mL}[/tex]
Divide.
[tex]\rho= 2.3 \ g/mL[/tex]
The density of the rock is 2.3 grams per milliliter.
A student titrated a solution containing 3.7066 g of an unknown Diprotic acid to the end point using 28.94 ml of 0.3021 M KOH solution. What is the molar mass of the unknown acid? Hint: you must write a balanced equation for the reaction.
Answer:
Molar mass of the diprotic acid is 424 grams
Explanation:
[hint: diprotic acid only contains 2 hydrogen protons]
Ionic equation:
[tex]{ \bf{2OH { }^{ - } _{(aq)} + 2H { }^{ + } _{(aq)}→ 2H _{2} O _{(l)} }}[/tex]
first, we get moles of potassium hydroxide in 28.94 ml :
[tex]{ \sf{1 \: l \: of \: KOH \: contains \: 0.3021 \: moles}} \\ { \sf{0.02894 \: l \: of \: KOH \: contain \: (0.02894 \times 0.3021) \: moles}} \\ { \underline{ = 0.008743 \: moles}}[/tex]
since mole ratio of diprotic acid : base is 2 : 2, moles are the same.
Therefore, moles of acid that reacted are 0.008743 moles.
[tex]{ \sf{0.008743 \: moles \: of \: acid \: weigh \: 3.7066 \: g}} \\ { \sf{1 \: mole \: of \: acid \: weighs \: ( \frac{1 \times 3.7066}{0.008743}) \: g }} \\ = { \underline{423.95 \: g \approx424 \: grams}}[/tex]
for the molar mass:
which statement correctly contrasts science and psuedoscience
Answer:
The correct answer is Science is objective, whereas pseudoscience is subjective. Pseudoscience includes beliefs, theories, or practices that have been or are considered scientific, but have no basis in scientific fact. This could mean they were disproved scientifically, can't be tested or lack evidence to support them.
Explanation:
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thank you
Which of the following does the atomic number of an atom represent? (1 point)
o the number of neutrons in the atom
O the number of particles outside the nucleus of the atom
O the number of protons in the atom
o the number of particles in the nucleus of the atom
Explanation:
the atomic number is the number of protons in the atom
aluminum has a density of 2.70 g/mL. Calculate the mass (in grams) of a piece of aluminum having a volume of 344 mL
Answer:
[tex]\boxed {\boxed {\sf 928.8 \ grams}}[/tex]
Explanation:
Density is the mass per unit volume of a substance. The following formula is used for calculating density.
[tex]\rho= \frac{m}{v}[/tex]
We know the density of aluminum is 2.70 grams per milliliter. The mass is unknown, but we know the piece of aluminum has a volume of 344 milliliters.
ρ= 2.70 g/mL v= 344 mLSubstitute these values into the formula.
[tex]2.70 \ g/mL = \frac {m}{344 \ mL}[/tex]
We are solving for the mass, so we must isolate the variable m. It is being divided by 344 milliliters. The inverse operation of division is multiplication. Multiply both sides of the equation by 344 mL.
[tex]344 \ mL *2.70 \ g/mL = \frac {m}{344 \ mL} * 344 \ mL[/tex]
[tex]344 \ mL *2.70 \ g/mL =m[/tex]
The units of milliliters cancel.
[tex]344 *2.70 \ g=m[/tex]
[tex]928.8 \ g =m[/tex]
The mass of the piece of aluminum is 928.8 grams.
2. Which of the following is the reason that ionization energy generally increases from left to right across the first period of the periodic table?
(A) As the atomic number increases, the electrons are harder to remove.
(B) Ionization energy increases as the atomic number increases in a period.
(C) As the atomic number increases, more electrons are
added to the atoms, thus increasing the electron-electron repulsions.
(D) As the atomic number increases, more protons in the
nucleus cause an increase in the effective nuclear charge,
making it harder to remove the electrons.
Answer:
The correct answer is D
Explanation:
more protons in the nucleus cause an increase in effective nuclear charge ,
Which pair of reactants for a Grignard reaction does not give 2-phenylbutan-2-ol after an aqueous workup?
what we can seprate sand and iron flings
Answer:
Magnetic separation
Explanation:
Sand is non-magnetic whereas iron fillings can be used as magnets. So, they can be separated by a method which uses a magnet for separating a mixture. Magnetic separation is the process which uses magnetic force for the extraction of magnetic material from a mixture.
through magnet
although not writable answer but for gk even a blow of wind shall do