Answer:
Burning yourself by touching boiling water would be conduction.
Explanation:
Why? I believe it would be because conduction means "transfer of" and the water is boiling and if you touch it, it burns you because it transfered heat to your skin causing you to feel a burning sensation.
Zachary adds 26.64 g to 12.557 g. How many significant figures should his answer have?
two
three
four
five
This answer should have four signifigant features
Explanation:
I had this on a test and got it right :D
A small bottle of water is left on the shore of a very large lake on an extremely cold winter night. What is most
likely to be observed the next morning? A). Both the lake and the bottles of water have become solid. B). The bottle of water has become solid but the lake has not. C). The lake has become solid but the bottle of water has not. D). Neither the bottle of water or the lake have become solid.
Answer:
A
Explanation:
Because it is a cold winter night making the lake freeze and the bottle is already solid.
What is the minimum number of significant digits in 828,000,000
Answer:
Answer:
Number of Significant Figures: 3
The Significant Figures are 8 2 8
Explanation:
you welcome
A student dissolves 10,3 g of sodium chloride(NaCl) in 250 g of water in a well-insulated open cup. She then observes the temperature of the water fall from 23.0 °C to 22.2 °C over the course of 3 minutes. Use this data, and any information you need from the ALEKS Data resource,
NaCl (s) rightarrow Na+ (aq) + Cl- (aq)
You can make any reasonable assumptions about the physical properties of the solution. Note for advanced students: it's possible the student did not do the experiment carefully, and the values you calculate may not be the same as the known and published values for this reaction.
1. Is this reaction exothermic, endothermic, or neither?
2. If you said the reaction was exothermic or endothermic, calculate the amount of heat that was released or absorbed by the reaction in this case.
3. Calculate the reaction enthalpy delta Hrxn per mole of NaCl.
Answer:
1
The reaction is exothermic
2
[tex]H = -1.1 \ KJ[/tex]
3
[tex]\Delta H_{rxn} = -6.24 \ KJ/ mol[/tex]
Explanation:
From the question we are told that
The mass of the sodium chloride is (NaCl ) is [tex]m_s = 10.3 \ g[/tex]
The mass of water is [tex]m_w = 250 \ g[/tex]
The initial temperature is [tex]T_i = 23^oC[/tex]
The temperature after 3 minutes is [tex]T_3 = 22.2 ^oC[/tex]
The time taken for temperature to fall is t = 3 minutes
The reaction is
[tex]NaCl_{ (s)} \rightarrow Na^+ _{(aq)} + Cl^-_{ (aq)}[/tex]
The reaction is exothermic because the temperature fell
Generally the mass of the solution is mathematically represented as
[tex]M = m_w + m_s[/tex]
=> [tex]M = 250 + 10.3 [/tex]
=> [tex]M = 260.3 \ g [/tex]
Gnerally the heat energy released from the solution is mathematically represented as
[tex]H = M * C_s * (T_3 - T_i)[/tex]
Here [tex]C_s[/tex] is the specific heat of solution which for this question we would assume it is the specific heat of water which has a value of
[tex]Cs = C_w = 4.18 J/g^oC[/tex]
So
[tex]H = 260.3 * 4.18 * (22- 23)[/tex]
[tex]H = -1088.054 \ J[/tex]
[tex]H = -1.088054 \ KJ[/tex]
[tex]H = -1.1 \ KJ[/tex]
Generally the number of moles of NaCl is mathematically represented as
[tex]nNaCl = \frac{m_s}{zNaCl}[/tex]
Here [tex]zNaCl[/tex] is the molar mass of NaCl and the value is
[tex]zNaCl = 58.44 \ g/mol[/tex]
So
[tex]nNaCl = \frac{10.3}{58.44 }[/tex]
=> [tex]nNaCl = 0.1762 \ moles[/tex]
Generally reaction enthalpy is mathematically represented as
[tex]\Delta H_{rxn} = \frac{H}{nNaCl}[/tex]
[tex]\Delta H_{rxn} = \frac{-1.1}{0.1762 }[/tex]
[tex]\Delta H_{rxn} = -6.24 \ KJ/ mol[/tex]
Which of the following is not an example of temperature abuse ?
Calculate the wavelength of light with an energy of 3.60x10^-19 J *
Explanation:
from E = mc^2 and de Broglie wavelength=h/mc
combine the eqns with respect to m(considering the body is moving with the speed of light(c))
then
E= hc/de Broglie wavelength
since, c= 3× 10^ 8
h= 6.626 × 10^ -34 and E is given, substitute the values.
sorry I don't have my calculator.
8. What is the density of a rock with a volume of 5 cubic centimeters and a mass of 3 grams?
Answer:
The answer is 0.6 g/cm³Explanation:
The density of a substance can be found by using the formula
[tex]density = \frac{mass}{volume} \\ [/tex]
From the question
mass = 3 g
volume = 5 cm³
We have
[tex]density = \frac{3}{5} \\ [/tex]
We have the final answer as
0.6 g/cm³Hope this helps you
What is an organ? List five (5) examples of organs?
Answer:
Here are all of the organ systems with some examples of organs found in each system:
Integumentary (skin, hair, nails)
Skeletal (bones)
Muscular (smooth, cardiac, and skeletal muscles)
Circulatory (heart, arteries, veins)
Respiratory (lungs, diaphragm, larynx)
Digestive (stomach, intestines, liver)
Explanation:
If an atom has an atomic number of 10 and an atomic mass number of 20, how many protons, neutrons, and electrons does it have?
Students are given a solid sample and asked to determine whether the sample is an element, compound, or mixture. One student observes that the sample is:
made up of particles of different colors, sizes, and shapes
some particles are softer than others
some shine while others appear dull
What can the students conclude about their sample?
It is an element.
It is a compound.
It is a homogeneous mixture.
It is a heterogeneous mixture.
Answer:
Compound
Explanation:
The sample given to the students is a mixture.
A mixture is composed of substances that are not chemically combined together. The components of a mixture all retain their individual properties. So in a mixture, we can easily notice the individual components if the mixture is heterogeneous.
Clearly, the students were given a heterogeneous mixture because one student observed that the sample is;
made up of particles of different colors, sizes, and shapes some particles are softer than others some shine while others appear dullBased on these observations, other students can agree that the sample is a mixture.
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A sample containing 16.93 metal pellets is poured into a graduated cylinder containing 11.2 of water, causing the water level in the to 19.7 Calculate the density of the metal.
Blank = g/ml
Answer:
The answer is 1.99 g/mLExplanation:
The density of a substance can be found by using the formula
[tex]density = \frac{mass}{volume} \\[/tex]
From the question
mass = 16.93 g
volume = final volume of water - initial volume of water
volume = 19.7 - 11.2 = 8.5 mL
We have
[tex]density = \frac{16.93}{8.5} \\ = 1.9917647058...[/tex]
We have the final answer as
1.99 g/mLHope this helps you
An element with 7 valence electrons will most likely
Answer:
An element with 7 valence electrons will most likely be a halogen and gain an electron
Explanation:
The element with 7 valence electrons is a halogen. Halogen group contains fluorine, chlorine, bromine, iodine and astatine.
What are halogens?Halogens are 17th group elements in periodic table. They are gases and shows high electronegativity. Halogens are p block elements.
The group number in periodic table is given assigned by adding 10 to the number of valence electrons if the no of valence electrons is 3 or more. Elements containing 1 or 2 valence electrons are in group 1 and 2 respectively.
Thus, if the number of valence electron 7 then, the element is in group 17 and it is a halogen.
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Someone plz hello me ASAP it would be appreciated on question 5 btw
Answer:
Option A kinetic energy
As the bow initially was at rest it had potential energy (an object at rest potential energy) and when it was at motion it will kinetic energy (object at rest will have kinetic energy)
what are the real primary colors
Answer:
red, yellow, blue are the 3 main primary colors
If an atom contains 11 protons and 12 neutrons, its ATOMIC NUMBER is: a 1 b 11 c 12 d 23
Answer:
B)11
Explanation:
The atomic number is the number of protons and electrons in an atom!!
HOPE THIS HELPS!!!!!!
Write the balanced net ionic equation for the reactions that occur when the given aqueous solutions are mixed. Include the physical states. A. copper(II) sulfate, CuSO4 , and potassium hydroxide, KOH net ionic equation: B. lithium carbonate, Li2CO3 , and aluminum nitrate, Al(NO3)3 net ionic equation: C. sodium phosphate, Na3PO4 , and barium chloride, BaCl2 net ionic equation:
Answer:
1. Cu(2+) [solution] + 2OH(-) [solution]= Cu(OH)↓ [solid]
2. 3CO3(2-) [solution] + 2Al(3+) [solution] + 3H2O [liquid] = 2Al(OH)3↓ [solid] + 3CO2↑ [gas]
2. 2PO4(3-) [solution] + 3Ba(2+) [solution] = Ba3(PO4)2↓ [solid]
Calculate the pressure on the ground if a prson of weight 450N was to
themselves on one heel of a stilleto shoe. one stilletto heel has an area of 1 square
centimetre.
Pls
Answer:
we will calculate the pressure in pascals:
The units of pascal are Newtons / m²
Since we are given the force in newtons but we are given the area in cm² , we will convert 1 cm² to 1 m²
we know that 1 cm² = (1 / 10000) m²
Now, plugging these values in the equation for pressure:
Pressure = Force (N) / Area (m²)
Pressure = 450 / (1 / 10000)
Pressure = 450 * 10,000
Pressure = 4,500,000 pa
Therefore, the stilleto shoe is applying a pressure of 4.5 million pascals on the floor
We can convert it to some other units from this information
This much Pressure will be equal to:
4,500 kPa (Kilo pascals)
4.5 MPa (mega pascals)
As chief chemist at Superior Analytical Products (SAP) you must design an experiment to determine the density of an unknown liquid to three (3) significant figures. The density is of the order of 1 g/cm3. You have approximately 7 mL of the liquid and only graduated cylinders and balances are available for your use. Which of the following combinations of equipment will allow you to meet but not exceed your goal?
a. graduated cylinder with +0.1 mL uncertainty, balance with :0.1g.
b. graduated cylinder with ±001 mL uncertainty: balance with 101 g uncertainty.
c. graduated cylinder with t0.01 mL uncertainty balance with t0 01 g uncertainty.
d. graduated cylinder with ±0 001 mL uncertainty, balance with 10001 g uncertainty.
Answer:
The correct answer is a
Explanation:
The formula for density is mass ÷ volume. Hence, a balance is required to determine the mass while a measuring/graduated cylinder is required to determine the volume.
The ideal measuring cylinder and balance to be used should have an uncertainty of just 0.1 ml and 0.1 g respectively. This reduces the chances of the answer gotten from the formula above to be more than 3 significant figures.
For example, if the volume to be used is 4.0 ml and the mass of this volume is 3.5 g, the density will be
Density = 3.5 ÷ 4
Density = 0.875 g/cm³ or 0.875 g/ml
NOTE that cm³ is the same measurement as mL
The answer above is in 3 significant figures
Which of the following transition is considered the phase
change from water to steam?
Answer:
the transition from water to steam is call evaporation.
Explanation:
water evaporates or vaporizes and turns into steam this typically happens when heat meets with the water. an example would be if you boil water steam will release from the pot, or when it rains, snows, etc (precipitation) the water evaporates and the ground dries.
Why is it difficult to hold and keep liquids like water in your hand? Guys please help
Answer:
Molecules move freely around since they don't have a definite shape. This is the reason water stays liquid and couldn't be gripped.
3. How does the independent variable (IV)
differ from the dependent variable (DV)?
Answer:
Independent variable in independent where the dependent variable relays on the independent one.
Explanation:
Look in the names and above.
Calculate the percent composition by mass of each element in LiClO2.
Given parameters:
Chemical specie = LiClO₂
Unknown:
Percentage composition of each specie = ?
Solution:
The percentage composition involves knowing the percent of total mass of a compound is made up of each of the constituent elements or groups.
Sum up the atomic masses and find the formula massDetermine percentage composition of each elementFormula mass of LiClO₂;
7 + 35.5 + 2(16) = 74.5g/mol
The percentage composition of each species are;
%Li = [tex]\frac{7}{74.5}[/tex] x 100 = 9.4%
%Cl = [tex]\frac{35.5}{74.5} x 100[/tex] = 47.7%
%O₂ = [tex]\frac{32}{74.5} x 100[/tex] = 43.0%
Carbon -11 is a radioactive isotope of carbon. It’s half life is 20 minutes. What amount of the initial mass of 70.0g of C -11 atoms in a sample will be left after 80 minutes
Answer:
4.38g
Explanation:
70.0/2 = 35g - 20 mins
35/2 = 17.5g - 40 mins
17.5/2 = 8.75g - 60 mins
8.75/2 = 4.375g - 80 mins
4.375 g of the carbon 11 would be remaining after 80 minutes.
Half life is the time taken for a substance to decay to half of its original value. It is given by:
[tex]N(t)=N_o(\frac{1}{2})^{\frac{t}{t_\frac{1}{2} } } \\\\\\Where\ t_\frac{1}{2}\ is\ half\ life,N_o\ is\ original\ amount,t\ is\ time,N(t)\ is\\amount\ remaining\\\\\\Given\ that\ N_o=70,t_\frac{1}{2}=20,t=80, hence:\\\\N(t)=70(\frac{1}{2} )^\frac{80}{20}=4.375\ g[/tex]
Therefore, 4.375 g of the carbon 11 would be remaining after 80 minutes.
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Which of the following describes a net force?
It is the total of the combined forces acting on an object.
It is the same thing as gravity.
It is a force that is part of the Internet.
It is the same thing as inertia.
Answer:
Net force is the vector sum of forces acting on a particle or body. ... Its associated torque, the net force, becomes the resultant force and has the same effect on the rotational motion of the object as all actual forces taken together.
Consider the following isotopic abundance data for argon (Ar) and silicon (Si):
Argon Isotope Isotopic Molar Mass 36 Ar 35.96755 g/mol Ar 37.96272 g/mol 40 Ar 39.96240 g/mol Abundance 0.337% 0.063% 99.600% Silicon Isotope Isotopic Molar Mass 25 Si 27.97693 g/mol 29 Si 28.97649 g/mol 30 Si 29.97376 g/mol Abundance 92.23% 4.67% 3.10%
Use the data to calculate the atomic masses of naturally occurring argon and silicon.
b) Calculate the number of atoms in 78.2 g of naturally occuring Si.
c) 42Ar is one of the longest lived radioactive isotopes of Argon. Mass spectroscopy data yields the following ratio of the mass of 42Ar to 40Ar: Mass of 42Ar Mass of 40Ar = 1.05006 use this ratio to find the atomic mass of 42Ar.
2. Pantoprazole, first sold under the brand name Protonix, is used for short-term treatment of erosive esophagitis associated with gastroesophageal reflux disease (GERD). The chemical formula for pantoprazole is C16H15F2N3O4S a) What is the molar mass of pantoprazole? b) How many molecules are in a 0.078 g sample of panotprazole?
Answer:
Explanation:
Molar mass of Argon
= 35.96755 x .00337 + 37.96272 x .00063 + 39.96240 x .99600
= .12121 + .0239165 + 39.80255
= 39.95
Molar mass of silicon
27.97693 x .9223 + 28.97649 x .0467 + 29.97376 x .0310
= 25.803 + 1.35320 + .929
= 28.08
b )
No of atoms of Si in 78.2 g = 78.2 x 6.02 x 10²³ / 28.08
= 16.76 x 10²³ .
c )
42 Ar / 40 Ar = 1.05006
42 Ar / 39.95 = 1.05006
42Ar = 41.95
2 )
C₁₆H₁₅F₂N₃O₄S
Mol weight = 16 x 12 + 1 x 15 + 2 x 19 + 3 x 14 + 4 x 16 + 32
= 192 + 15 + 38 + 42 + 64+ 32
= 383
No of molecules = .078 x 6.02 x 10²³ / 383
= 1.226 x 10²⁰ molecules .
Answer:
It's too short. Write at least 20 characters to explain it well.
Explanation:
Hold on, our servers are swamped. Wait for your answer to fully load.
Which phase has the greatest structure
Answer:
The answer is D
Explosion:
it depends on the solid,liquid,gas and the tempcher
Which is most likely a covalent compound?
LiF
MgS
NH3
CaCl2
Answer:
NH3 is the most likely covalent compound
Explanation:
Other Choices are:
LiF- Ionic compound
MgS- ionic compound
CaCl2- ionic compound
The most likely to have a covalent bond is NH₃. The correct option is c. covalent bonds are the strongest bonds among all.
What are covalent bonds?A covalent bond is formed between two atoms by the mutual sharing of one or more pairs of electrons. The two atomic nuclei attract these electrons at the same time. When the difference in electronegativities of two atoms is too tiny for electron transfer to produce ions, a covalent bond occurs.
The unequal sharing of electrons between the combining atoms results in the formation of a polar covalent bond. The equal sharing of electrons between the combining atoms results in the formation of a non-polar covalent bond.
LiF- Ionic compound
MgS- ionic compound
CaCl₂- ionic compound
Therefore, the correct option is c, NH₃.
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A student performs an experiment where gas is collected over water in an upside down graduated cylinder. If the atmospheric pressure is 745 mmHg and the level of water in the graduated cylinder is 14.4 cm higher than the level of the water exposed to the atmosphere, what is the total pressure of gases inside the graduated cylinder? Enter your answer numerically in units of mmHg.
Answer:
601mmhg
Explanation:
Pgas = Patm - hρg
Height of water = 14.4cm
Convert to mm
1 cm = 10mm
14.4 cm =
= 14.4cm × 10mm
= 144mm
hpg = 144 mmhg
Ptotal = Patm - hog
= 745mmhg - 144 mmhg
= 601mmhg
The total pressure of gases inside the graduated cylinder = 601mmhg
Answer?????????????????????????????!!?!?!?!,!?!?!?
Answer:
why cant you just say the grasshopper eats the marsh grass the shrew eats the grasshopper and the hawk eats the shrew.
Explanation:
this makes sense to me but im not sure.
Answer:
the hawk eats both the snake and the shrew and so does the snake eat the shrew and frog and ex...
Explanation:
What kind of charge do electrons have
Answer:
An electron has a Negative charge or -1