1. The density of a substance is 4.8 g/mL. What is the volume of a
sample that is 19.2 g?
Answer:
d= 4.8g/mL
m= 19.2 g
V=m/d
V= 4 mL
Q1.What is the mass of 5 moles Of 1.Mg 2.CaCO3 Q2. Calculate the number of atoms in 10g of Na Q3.calculate the number of molecules in 10g of NaCl Q.4.What is Avogadro's number? How many number of atoms are present in 4g of Oxygen?
Answer:
Explanation:
Q1) as we know that moles=given mass/molar mass
mass of 5 moles of Mg is
mass =moles*molar mass
mass=5*24
mass=120 g
mass of 5 moles of CaCO3 is
mass= moles*molar mass
mass=5*100=500
Q2) number of atoms in 10 g Na
first we need number of moles of sodium
moles =mass/molar mass
moles=10/23=0.43
now we know that moles=number of atoms /avogadro number
for number of atom the formula become
number of atom=moles*avogadro number
number of atom=0.43*6.023*10^23=2.6*10^23
Q3)number of molecule in 10 g of NaCl
again we need number of moles of NaCl
moles=given mass/molar mass
moles=10/58.5=0.17
now number of molecules=moles*avogadro number
number of molecules=0.17*6.023*10^23=1.02*10^23
Q4) avogadro number is the number of particles(atoms,molecules,ions) present in one mole of a substance its value is 6.023*10^23
Q5)Number of atoms in 4g of oxygen
again we need number of moles of oxygen
moles=mass/molar mass
moles=4/16=0.25
now number of atoms=moles*avogadro number
number of atoms=0.25*6.023*10^23 =1.5*10^23
how are protons and neutrons found?
Answer:
Electrons are found in shells or orbitals that surround the nucleus of an atom. Protons and neutrons are found in the nucleus. They group together in the center of the atom.
Explanation:
I'm not sure if this is correct but I hope this helps.
This element has nine more electrons than Technetium
Answer:
Tellurium
Explanation:
Technetium's position on the periodic table is 43 and Tellurium's is 52
An ice cream company decides to make a new lower calorie flavor,but testers reported that the flavor wasnt as good as the original.Is this an example of trade off
Answer:
Yes, the given instance is an example of a trade-off.
Explanation:
The trade-off seems to be a strategy to minimize or surrender one or more favorable results in consideration for increasing either receiving other favorable results to optimize cumulative benefit or efficacy within such conditions.The above is indeed a trade-off since the participants are experimenting in exchange again for ice cream individuals have to enjoy. The ice cream manufacturer always gets a review of the technician in exchange for free ice cream.Radar detectors use radio waves to measure the speed of moving
vehicles. Radar detectors have a wavelength of 1.8 meters. What is the frequency of waves from a radar detector?
Answer:
1.7x10^8 Hz
Explanation:
Frequency could be explained as the number of occurrences of a repeating event at a time
Given:
wavelength = 1.8 meters
The frequency f of the waves can be calculated using f = c / λ
Where c (m/s) is the speed of the wave
λ (m) is the wavelength
Speed c= 3*10^8 m/s
Frequency f= 3*10^8 /1.8
Frequency= 1.7x10^8 Hz
Therefore,the frequency of waves from a radar detector is 1.7x10^8 Hz
Please answer this question, I will give brainliest! You fill a 2.0 L metal thermos with gas at room temperature (25.0 ˚C) and 1.0 atm. Put it in the freezer and the temperature drops to -15.0 ˚C. A. What is the pressure inside the thermos after it cools, in atm? Justify your answer. B. . … and what is that pressure in mmHg?
e temperature of a 0.750 L gas sample at 25°C and 2.00 atm is changed to 250°C.
What are some tips *from a girl* to get a girl to like you without making it obvious
What kind of questions CANNOT be answered by chemistry?
If someone could help me out I would really appreciate it! Thank you!
Answer:
d. why matter exists
Explanation:
The kind of questions that chemistry CANNOT answer is "why matter exists".
In Chemistry, question of how the properties, composition and structure of substances are is answered. Also, the transformations that these substances undergo, and the energy that they release or absorbe during the transformation processes are revealed in chemistry.
Chemistry can answer the question of what forms of matter exists but cannot answer why matter actually exists.
Atoms of hydrogen can become helium atoms during a chemical reaction.
True
False
Answer:
false
in chemical reaction element doesnot change into another
Explanation:
1. Which statement best describes why a gas is
easily compressible while most solids
are incompressible?
A. The molecules of a gas are much smaller
than those of a solid.
B. The molecules of a solid are not attracted to
one another.
C. The molecules of a gas are much further
apart than those of a solid.
D. The molecules of a solid are much larger
than those of a gas.
C) The molecules of a gas are much further
apart than those of a solid.
A gas is easily compressible while most solids are incompressible because the molecules of gas are much further apart than those of a solid.
What are gases?Gases is one of the four fundamental state of matter.
Gases can be defined as phase of matter that neither have fixed shape nor have fixed volume.
The molecules of gases are far apart from each other as compare to other phases of matter.
The change in properties of volume is known as compressibility and those fluid whose volume changes are known as compressible fluids or gases.
The fluids which does not compressed or expanded and its volume remain constant are known as incompressible fluids or gases.
Thus, gas is easily compressible while most solids are incompressible because the molecules of gas are much further apart than those of a solid.
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An ionic bond for calcium and oxygen is CaO. If an oxygen ion has a charge of two negative, what is the charge for calcium? +2 –1 +1 –2
Answer:
+2
Explanation:
2. Which of the following statements correctly explains the difference between a theory and a scientific law?
O Scientific laws are not as well proven as theories.
O Scientific laws are statements about observed experimental facts, while theories are explanations of natural phenomena.
Theories are not as well proven as scientific laws.
O Scientific laws explain natural phenomena while theories are just guesses.
Answer:
pretty sure its Scientific laws are statements about observed experimental facts, while theories are explanations of natural phenomena.
The statement that correctly explains the difference between a theory and a scientific law is as follows:
Scientific laws are statements about observed experimental facts, while theories are explanations of natural phenomena.Thus, the correct option is B.
What is Scientific theory?A Scientific theory may be defined as a well-explained fact that is significantly associated with the natural world that has been constructed through the utilization of the scientific method, and which brings together many facts and hypotheses.
A Scientific theory is based on observation. It is proven but still testable in nature in order to derive evidence. It generally does not possess mathematical statements and deductions. Theories are explained on nature as well as natural phenomena.
Scientific law is based on unalterable facts or those facts that remain constant. It is proven as well as contains evidence to support the claim. It definitely possesses mathematical statements and deductions.
Therefore, the correct option for this question is B.
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Do you think the density of the rock models affects the melting rate? Why or why not? I said no, but I need help on the part that says why or why not. Please use your own knowledge. Looking it up won't help. I have tried. :)
Answer:
1) Yes the density does affect it's melting rate.
Explanation:
Simply because the more rock the more time. For instance an ice cube that is empty inside ( has less density ) will take less to melt. Verses an ice cube that is ice to its inner core ( has more density ) will take more time to melt in the same temperature as the first ice cube.
11. Calculate the number of atoms of sodium in a 4.5-gram sample.
A 1.2 x 1023 atoms Na
B 2.5 x 1023 atoms Na
C 1.7 x 10-22 atoms Na
D 3.1 x 1024 atoms Na
Answer:
A
Explanation:
Find the probability that 200 tosses of a coin will result in (a) between 80 and 120 heads inclusive, (b) less than 90 heads,(c)less than 95 heADS (D) EXACTLY 100 heads
Answer:
between 80 to 120
Explanation:
because it would be around 100 but it can't be exact.
Is this atom Reactive (unstable) or Unreactive (stable) ?
Answer:
The answer is Unreactive.
Explanation:
This is an unreactive atom because it has completely filled out stable electrons in the outer shell.
8 electrons in the outer shell means stable.
A(n) __________________ is a statement of what you think will happen during an investigation. It is often written in the form of an if... Then... Because statement. Group of answer choices
Answer:
Hypothesis. Hope this helped! :)
Which property is a physical property?
A:malleable
B:becomes moldy quickly
C:easy to digest
D:does not burn
Answer:
The answer is B. Becomes moldy quickly.
Explanation:
This is the most logical answer out of all of them an I took the test.
Please help Which of the following is the SI unit used to measure length? a.kilogram b.liter c.meter d.Kelvin
A. kilogram is the SI unit used to measure mass of body.
1 kilogram = 100 gramB. litre is the SI unit used to measure volume of substance.
1 litre = 10ˉ³ m³C. meter is the unit used to measure length of body.
1 meter = 100 centimetersD. Kelvin is the unit used to measure temperature of body.
1 K = -273.15 °CHence, (B) is the correct answer!
Cheers!
In coulombs, how much positive charge is there IN a barium nucleus? On a barium ion?
Answer:
The amount of positive charge in a barium nucleus is approximately 8.972 × 10⁻¹⁸ coulomb
Explanation:
The amount of positive charge there is in a barium nucleus is found as follows;
The atomic number of an element is equal to the number of proton present in the atom
The atomic number of barium = 56 = The number of protons in an atom of barium
The positive charge of a single proton is known as an elementary charge, e, given by the formula, e = F/N[tex]_A[/tex]
Where;
F = Faraday's constant
N[tex]_A[/tex] = The Avogadro's number
Therefore, e = 1.602 176 634 × 10⁻¹⁹ C
Which gives the positive charge, Q, of the protons of a barium nucleus as follows;
Q = Number of protons × e
Q = 1.602176634 × 10⁻¹⁹ × 56 ≈ 8.972 × 10⁻¹⁸ Coulomb per atom of barium.
The amount of positive charge in a barium nucleus ≈ 8.972 × 10⁻¹⁸ coulomb.
What is the atomic number of an atom that has 5 neutrons and 4 electrons
The atomic number is 4.
The atomic number of the given atom is equal to 4.
What is the atomic number?The atomic number (symbol Z) of a chemical element can be defined as the charge number of an atomic nucleus. For an ordinary atom, the atomic number is equal to the number of protons found in the nucleus of an atom of that element.
The atomic number helps to uniquely identify ordinary chemical elements. In an ordinary uncharged atom or neutral atom, the atomic number of that atom is also equal to the number of electrons.
For a neutral atom, the sum of the atomic number and the neutron number gives the atomic mass. The protons and neutrons have approximately the same mass. Atoms that have the same atomic number but different numbers of neutrons or different mass numbers are known as isotopes.
Given the number of electrons in the atom is 4. Therefore, the atomic number of that atom will be equal to 4.
Learn more about the atomic number, here:
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Which is more viscous - petrol or diesel?
Answer:
Petrol....follow me and mark me brainliest
Answer The answer to this question is diesel.
Explanation:
Hi there, hope this helps!
To separate a mixture of iron filings and salt, the most efficient method would be
Answer:
Explanation:
Of course you could do the separation chemically. Dissolve the salt up in water, pass thru a filter, wash the iron filings with ethanol, which would encourage the salt to precipitate from solution.
I do hope I helped you! :)
Answer:
by passing a magnet through the mixture
Explanation:
A calorimeter made from a can is used to measure the calories in a peanut. During the experiment, the
measured calories were 35% of the true/accepted value given by references
Answer:
The heat generated per gram of sample in calories is 0.87 g
Explanation:
Given that,
A calorimeter made from a can is used to measure the calories in a peanut.
During the experiment, the measured calories were 35% of the true/accepted value given by references
Suppose, the mass of peanut is 0.4 g and find the
We need to calculate the heat generated per gram of sample in calories
Using formula of heat generated
[tex]q=\dfrac{q_{penut\ calorimeter}}{m_{peanut}}[/tex]
Put the value into the formula
[tex]q=\dfrac{0.35}{0.4}[/tex]
[tex]q=0.87\ g[/tex]
Hence, The heat generated per gram of sample in calories is 0.87 g
If I fill a tall glass with water and then transfer the water to a shorter glass, it appears there is more water. Is there more water?
SHOW YOUR WORK!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
An experiment was conducted to find the mass of one mole of carbon atoms. The results of the experiment showed that a mole of carbon atoms had a mass of 15.78 g. The accepted value of a mole of carbon atoms is 16.00 grams. What is the percent error in this experiment?
Answer:
1.375%
Explanation:
Percent Error = measured value - accepted value/ accepted value x 100
Measured Value: 15.78
Accepted Value: 16.00
Work:
[tex]\frac{15.78-16.00}{16.00}[/tex] * 100
[tex]\frac{-.22}{16}[/tex] * 100 = -1.375
You cannot have a negative percentage. Therefore the answer is 1.375%
Some chemical reactants are listed in the table below. Complete the table by filling in the oxidation state of the highlighted atom.
Answer:
1. Cu = +2
2. O = – 2
3. C = +2
4. N = 0
Explanation:
Note:
A. The oxidation state of oxygen is always – 2 except in peroxides where it is – 1.
B. The oxidation state of Hydrogen is always +1 except in metallic hydrides where it is – 1.
Now let us solve the question given above.
1. CuO = 0 (ground state)
Cu + O = 0
O = – 2
Cu + (– 2) = 0
Cu – 2 = 0
Collect like terms
Cu = 0 + 2
Cu = +2
2. H2O = 0 (ground state)
2H + O = 0
H = +1
2(1) + O = 0
2 + O = 0
Collect like terms
O = 0 – 2
O = – 2
3. CO = 0 (ground state)
C + O = 0
O = – 2
C + (– 2) = 0
C – 2 = 0
Collect like terms
C = 0 + 2
C = +2
4. N2 = 0 (ground state)
2N = 0
Divide both side by 2
N = 0/2
N = 0
Which of the following are fluids
What does a straight line represent on a distance vs time graph?
Answer:
It represents the relationship between the distance travelled and time spent as constant or at a stop.
Explanation:
This is because as the line progresses, the time increases the distance should change as well my moving up or down, in a linear equation this relationship is constand but if the line is horizontal though, the distance is not changing despite time passing which means it has come to a stop.