Answer:
Identifies the number of protons a single atom of the element contains.
Explanation:
The atomic number helps people identify elements according to the number of protons one atom of the element has. It essentially defines the element.
While having a neutral charge, it also provides the number of electrons the element has (in one atom).
How many milliliters of an aqueous solution of 0.157 M magnesium nitrate is needed to obtain 17.4 grams of the salt?
Answer:
747mL of the 0.157mL are needed
Explanation:
To find the grams of salt we need to convert these grams to moles using molar mass of magnesium nitrate (148.3g/mol). Then, with the molar concentration we can convert the moles to liters and, as last, to milliliters, as follows:
Moles Mg(NO₃)₂:
17.4g * (1mol / 148.3g) = 0.117 moles of magnesium nitrate
Volume:
0.117 moles * (1L / 0.157moles) = 0.747L
= 747mL of the 0.157mL are needed
In a 0.157M solution there are 0.157 moles per liter of solution
Which of the following has a nonpolar bond? *
02
HCI
NH3
CH4
Answer: CH4
Explanation:
BRAINLESS PLEASE
Answer:
O₂
Explanation:
The example of the compound or the molecule that forms a non-polar bond is oxygen gas.
Oxygen gas has a formula of O₂
Since this is a homonuclear molecule, the two bonding atoms have the same kind of electronegativity. The difference is therefore zero. In such a molecule, there is equal sharing of the electron pair between the atoms and no electrostatic charge on the molecule.Potassium hydroxide has the chemical formula KOH. It feels slippery and is used in cleaning liquids. Based on this description, potassium hydroxide is most likely a(n) A acid. B base. с neutral solution. D pH indicator.
Answer:
it should be a base
Explanation:
this is because solutions such as bleach are usually slippery on the hands, and mostly bases are in cleaning solutions
Select the best answer from the choice below. When the wavelength decreases, the frequency:
Answer:
Increases
Explanation:
Frequency and wavelength of lights are inversely proportional to each other.
The wave of light having highest frequency have shortest wavelength and the light with the shortest frequency having highest wavelength.
Formula:
Speed of light = wavelength × frequency
c = λ × f
λ = c/f
This formula shows that both are inversely related to each other.
The speed of light is 3×10⁸ m/s
Frequency is taken in Hz.
It is the number of oscillations, wave of light make in one second.
Wavelength is designated as "λ" and it is the measured in meter. It is the distance between the two crust of two trough.
What was the test or tests that made you decide if you compound was an aldehyde or a ketone and why?
Answer:
Tollen's test or silver mirror test is use to distinguish between ketone and aldehyde.
Explanation:
Tollen's test is use to distinguish aldehyde from ketone because Tollen reagent consist of silver nitrate and ammonia and it oxidized aldehydes to carboxylic acid and the silver Ag+ is reduced to solid silver Ag. It form a inner film wall on the tube that look like mirror. Ketone do not react with Tollen reagent and therefore does not form silver mirror on the tube wall.
Chemistry of Life Practice Active 8 1 What type of organic compound is used for building cell parts?
Answer:
Carbohydrates
Explanation:
Calculate the percentage difference in the fundamental vibrational wavenumbers of 23Na35Cl and 23Na37Cl on the assumption that their force constants are the same. The mass of 23Na is 22.9898mu.
Answer:
1.089%
Explanation:
From;
ν =1/2πc(k/meff)^1/2
Where;
ν = wave number
meff = reduced mass or effective mass
k = force constant
c= speed of light
Let
ν =1/2πc (k/meff)^1/2 vibrational wave number for 23Na35 Cl
ν' =1/2πc(k'/m'eff)^1/2 vibrational wave number for 23Na37 Cl
The between the two is obtained from;
ν' - ν /ν = (k'/m'eff)^1/2 - (k/meff)^1/2 / (k/meff)^1/2
Therefore;
ν' - ν /ν = [meff/m'eff]^1/2 - 1
Substituting values, we have;
ν' - ν /ν = [(22.9898 * 34.9688/22.9898 + 34.9688) * (22.9898 + 36.9651/22.9898 * 36.9651)]^1/2 -1
ν' - ν /ν = -0.01089
percentage difference in the fundamental vibrational wavenumbers of 23Na35Cl and 23Na37Cl;
ν' - ν /ν * 100
|(-0.01089)| × 100 = 1.089%
Answer:
1.089%
Explanation:
From;
ν =1/2πc(k/meff)^1/2
Where;
ν = wave number
meff = reduced mass or effective mass
k = force constant
c= speed of light
Let
ν =1/2πc (k/meff)^1/2 vibrational wave number for 23Na35 Cl
ν' =1/2πc(k'/m'eff)^1/2 vibrational wave number for 23Na37 Cl
The between the two is obtained from;
ν' - ν /ν = (k'/m'eff)^1/2 - (k/meff)^1/2 / (k/meff)^1/2
Therefore;
ν' - ν /ν = [meff/m'eff]^1/2 - 1
Substituting values, we have;
ν' - ν /ν = [(22.9898 * 34.9688/22.9898 + 34.9688) * (22.9898 + 36.9651/22.9898 * 36.9651)]^1/2 -1
ν' - ν /ν = -0.01089
percentage difference in the fundamental vibrational wavenumbers of 23Na35Cl and 23Na37Cl;
ν' - ν /ν * 100
|(-0.01089)| × 100 = 1.089%
How would one use a Grignard-based synthesis to accomplish the following transformation? benzyl bromide (PhCH2Br) to 3-phenyl-1-propanol 1. Mg, Et20 2. ethylene oxide3. H3O+ 1. Mg, Et2O 2. Ethanol3. H3O+ 1. Mg, Et202. Ethylene 3. H3O+ None of the above.
Answer: ghfbg
Explanation: fgfghfg
Which elements-O2, Rb, Sb, Pt, Y, Sm, Mn, Rh, Sn, Li-will react (a) with a solution of I to generate I2; (b) with a solution of Ag' to generate Ag; and (c) with a solution of Nat to generate Na?
Answer:
a) O2, Pt, Rh
b) Rb, Y, Sm, Mn, Sn, Li
c)Rb
Explanation:
We must consider the reduction potentials of each of the species in the question.
In (a) above, all the elements whose reduction potential is higher than the redox potential for the oxidation of I^- will react with a solution of I^- to generate I2 as shown above.
In (b) above, all the strong reducing agents can donate electrons to Ag^+ and reduce it to Ag as shown above.
In (c) Rb has a more negative reduction potential than sodium hence it can react with a solution of sodium salt to generate sodium metal.
What two options are homogeneous mixture
Answer:
vinegar and soap
Explanation:
Answer:
vinegar and soap
Explanation: just took the test
the difference in energy between the n=1 and n=2 energy levels in a hydrogen atom is 1.64x10^-18 J. what happens when an electron in a hydrogen atom transitions from n=2 to n=1?
Answer:
It emits 1.64 x 10⁻¹⁸J of energy
Explanation:
The n = 1 is a lower quantum level compared to n = 2.
When a hydrogen atom moves from a higher level to a lower one, it simply emits the energy difference between the two levels.
If a hydrogen atom moves from a lower energy level to a higher one such as from 1 to 2, they absorb the energy difference to attain the new excited state. So, for an electron in the hydrogen atom to move from a higher energy level to a lower one, it must emit 1.64 x 10⁻¹⁸J of energy.A gas has a volume of 6.00 liters at a temperature of 27° C and a pressure of 1,00 atm. What is the volume of the gas, in liters, at a temperature of 327°C and a
pressure of 3.00 atm?
We are given:
P1 = 1 atm P2 = 3 atm
T1 = 300 K T2 = 600 K
V1 = 6 L V2 = v L
Finding the final Volume:
From the ideal gas equation:
PV = nRT
since in the given scenario, the universal gas constant (R) and number of moles(n) are constant
So, for both the cases, the value of n*R will be a constant k
Hence, we can write that:
PV / T = k [where k is a constant]
Since the constant 'k' is the same for both the cases, we can write that:
P1V1 / T1 = P2V2 / T2
replacing the variables
1 * 6 / 300 = 3 * v / 600
1/50 = v / 200
v = 200/50
v = 4 L
Therefore, the volume of the gas at 600K and 3 atm will have a volume of 4 L
Dr. Simmons wants to make sure her scientific investigation is considered good. She knows that for an experiment to produce valid results, it must adhere to accepted methods. Which procedure would she not include as part of her valid scientific experiment?
a) organized procedures
b) controlled surroundings
c)precise observations
d) uncontrolled variables
The procedure that Dr. Simmons will not include as part of her scientific experiment is uncontrolled variables.
When a scientific investigation is carried out, experiments are used as a method of verifying results. Generally, when an experiment is carried out, you want to verify that given circumstances generate a specific result.
The experiments must be as controlled as possible so that they can be repeated and thus create reliable laws. Therefore, Dr. Simmons will not include uncontrolled variables in her experiment, because these variables can modify the result of an investigation in many ways and limit the production of new knowledge.
Uncontrolled variables are generally not included in scientific investigations because they cannot be modified and they influence various results that cannot be considered reliable knowledge.
Learn more in: https://brainly.com/question/3109450
A weather balloon with a volume of 3.40774 L
is released from Earth’s surface at sea level.
What volume will the balloon occupy at an
altitude of 20.0 km, where the air pressure is
10 kPa?
Answer in units of L.
Answer: The volume at an altitude of 20.0 km is 34.5289 L
Explanation:
Boyle's Law: This law states that pressure is inversely proportional to the volume of the gas at constant temperature and number of moles.
[tex]P\propto \frac{1}{V}[/tex] (At constant temperature and number of moles)
[tex]P_1V_1=P_2V_2[/tex]
where,
[tex]P_1[/tex] = initial pressure of gas = 101.325 kPa ( at sea level)
[tex]P_2[/tex] = final pressure of gas = 10 kPa
[tex]V_1[/tex] = initial volume of gas = 3.40774 L
[tex]V_2[/tex] = final volume of gas = ?
Now put all the given values in the above equation, we get the final volume of gas.
[tex]101.325\times 3.40774=10\times V_2[/tex]
[tex]V_2=34.5289L[/tex]
Thus the volume at an altitude of 20.0 km is 34.5289 L
Therefore, the final pressure of the gas will be 3.75 atm
i really need help with the rest of this assignment. theres 10 pages of multiple choice questions, i can mark brainliest and pay money if you help me :)
Answer:
Hey! I'll help you.
Explanation:
I got your back.
Using the two models, compare the processes of nuclear fusion and nuclear fission. What do the two processes have in common?
Choose all that apply.
A)
Energy is released.
B)
Elements are created
0)
A chain reaction occurs.
D)
Besides energy, neutrons are released.
E)
Both processes begin with an unstable nucleus.
Answer:it’s A and B
Explanation:
Answer:
A and B
Explanation:
They’re both fusion.
What is the work function of gold metal in kJ/mol if light with λ = 234 nm is necessary to eject electrons?
Answer
512kj/mole
Explanation:
What is the work function of gold metal in kJ/mol if light with λ = 234 nm is necessary to eject electrons?
The energy can be calculated using below expresion;
E = hc/λ
Where h= planks constant= 6.626 x 10^-34
c= speed of light= 3 x 10^
λ= wavelength
hc= (6.626 x 10^-34 x 3 x 10^ 8)
=
a solution is dilute when?
A. it has a lot of solute
B. has little solvent
C. it has a lot of solvent
D. has maximum solute
Lake Michigan holds 13 billion gallons of water. If just Chicago removed water from the lake and it never rained again, how many decades would the water last?
Answer:
Check explanation section.
Explanation:
In order to be able to answer this question accurately,there is need to follow the formula below for the calculation;
Numbers of decades = total volume/ volume per decade. ----------------------(1).
So, we are given from the Question above that the volume of water in Lake Michigan = 13 billion gallons of water.
And if chicago uses 5 million gallons of water every decade.
Therefore, using the formula (1) above, we have;
Numbers of decades = 13 × 10^9/ 5 × 10^6 = 2.6 × 10^15 decades.
Each of the two different solids A and B melts at 133 o C. A sample of an unknown solid melts around 133 o C, and is either A or B. How will you determine the identity of the unknown solid
Answer:
See explanation
Explanation:
The melting point range of a pure compound is about 1-2ºC of the expected melting point. An impure solid melts within a range that is both larger than that of the pure substance (>1ºC) and begin at a lower temperature because impurities decrease the meting point. A melting range of 5º or more indicates that a compound is impure.
Since the melting points of A and B are estimated at 133 o C, the melting point range for each pure substance must be slightly different from each other. The melting point of the unknown is measured and its range is compared with the melting point ranges of pure A and B then decision can now be made about the identity of the unknown solid.
Calculate the pH of a buffer solution when 32.0 mL of a 0.25 M H2CO3 is mixed with 20.0 mL of a 0.15 M NaHCO3
pH of buffer solution : 4.32
Further explanationA buffer solution is a solution that can maintain a good pH value due to the addition of a little acid or a little base or dilution.
The buffer solution can be acidic or basic
Acid buffer solutions consist of weak acids(H₂CO₃) and their salts.(NaHCO₃)
mol H₂CO₃
[tex]\tt 0.032\times 0.25=0.008[/tex]
mol NaHCO₃
[tex]\tt 0.02\times 0.15=0.003[/tex]
[tex]\tt [H^+]=Ka\dfrac{mole~weak~acid}{mole~salt}\\\\(H^+]=1.8\times 10^{-5}\dfrac{0.008}{0.003}=4.8\times 10^{-5}\\\\pH=5-log~4.8=4.32[/tex]
Other than the starting material, 2-methylcyclohexanol, what base or bases are present in the dehydration reaction mixture to participate in proton transfers?
a) H2PO4- only
b) H2O and H2PO4-
c) H2O and HSO4-
d) H2O only
Answer:
c) H2O and HSO4-
Explanation:
The dehydration of 2-methylcyclohexanol occurs in the presence of H2SO4. Recall that acids are proton donors in solution; the equilibrium shown below is then set up,
H2SO4(aq) + H2O(l) ⇄H3O^+(aq) + HSO4^-(aq)
The species H2O and HSO4- are two proton acceptors in the system. According to the Brownstead- Lowry definition, a base is a proton acceptor in solution.
Hence H2O and HSO4- are bases present in the dehydration of 2-methylcyclohexanol.
What does this image represent?
Amine group
Carbonyl group
Ether group
Hydroxyl group
Answer:
ether group
Explanation: I looked it up
Use the image to complete the sentences.
At left a grid labeled A of regularly arranged orange balls with small movement lines near each. At right a grid labeled B of regularly arranged orange balls with large movement lines near each.
Two different substances, Substance A and Substance B, are in direct contact with each other and are at different temperatures.
The particles in Substance B are vibrating
the particles in Substance A. This means Substance B is
Substance A and conduction will
.
Answer:
1. FASTER THAN- #2
2. WARMER THAN #1
3. OCCUR FROM SUBSTANCE B TO SUBSTANCE A- #3
Explanation:
I did the assignment On edg And got it right
Answer:
Use the image to complete the sentences.
At left a grid labeled A of regularly arranged orange balls with small movement lines near each. At right a grid labeled B of regularly arranged orange balls with large movement lines near each.
Two different substances, Substance A and Substance B, are in direct contact with each other and are at different temperatures.
The particles in Substance B are vibrating
✔ faster than
the particles in Substance A. This means Substance B is
✔ warmer than
Substance A and conduction will
✔ occur from Substance B to Substance A
.
Explanation:
I know im late
Balance chemical equation hbr(aq)+o2(g) h20+br2
Answer:
2HBr + O2 = H20 +Br2
Explanation:
Answer:
4hbr(aq) + O2(g) = 2H2O + 2Br2
Explanation:
an ionic bond forms when atoms blank electrons
Answer:
An ionic bond forms when atoms transfer electrons.
Explanation:
Ionic bonds are formed when atoms transfer electrons. (In contrast, covalent bonds are formed when atoms share electrons.)
There's a distinction between the two: when two atoms react to form an ionic bond, one atom would completely lose one electron, while the other would completely gain that electron. The atom that loses the electron becomes a positively-charged ion called a cation, whereas the atom that gains the electron becomes a negatively-charged ion called an anion.
For example, consider the reaction between a sodium [tex]\rm Na[/tex] atom and a chlorine [tex]\rm Cl[/tex] atom: [tex]\rm Na + Cl \to NaCl[/tex].
When the sodium atom and the chlorine atom encounter, the sodium atom would lose one electron to form a positively-charged sodium ion, [tex]\rm Na^{+}[/tex]. The chlorine atom would gain that electron to form a negatively-charged chlorine ion [tex]\rm Cl^{-}[/tex].
These two ions will readily attract each other because of the opposite electrostatic charges on them. This electrostatic attraction (between two ions of opposite charges) is an ionic bond.
Overall, it would appear as if the sodium [tex]\rm Na[/tex] atom transferred an electron to the chlorine [tex]\rm Cl[/tex] atom to form an ionic bond.
In contrast, when two atoms react to form a covalent bond, they share electrons without giving any away completely. Therefore, it is possible to break certain covalent bonds apart (using a beam of laser, for example) and obtain neutral atoms.
On the other hand, when an ionic bond was broken, the result would be two charged ions- not necessarily two neutral atoms. The electron transfer could not be reversed by simply breaking the bond.
For example, when table salt [tex]\rm NaCl[/tex] is melted (at a very high temperature,) the ionic bond between the sodium ions and chloride ions would (mostly) be broken. However, doing so would only generate a mixture of [tex]\rm Na^{+}[/tex] and [tex]\rm Cl^{-}[/tex] ions- not sodium and chlorine atoms.
Answer:yea it’s transfer
Explanation:
How many more electrons are there in the last energy level of phosphorus, atomic
number 15, than there are in the last principal energy level of neon, atomic number 10?
sorry but I need some three point so that's why I didn't
How would you synthesize 1-hexanol starting from 1-propanol, incorporating a Grignard reagent in the synthesis?
Answer:
hjhjhjhhhhh
Explanation:
In frequency modulation, which wave property remains constant?
Answer:
The correct answer is - Amplitude.
Explanation:
Frequency modulation is a method or procedure that sends or transmits the signals such as radio broadcasting, telecommunication where the value of the transmitted signal is provided by the frequency of a high-frequency wave that carries the signal.
In this method of encoding the information, the amplitude of the carrier remains the same or constant but frequency varies in accordance with the modulating signal.
Answer:
The answer is C Amplitude
Explanation:
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Which statement describes how phase changes
can be diagrammed as a substance is heated?
A. The phase is on the y-axis and thels
temperature is on the x-axis.
B. The temperature is on the y-axis and the
phase is on the x-axis.
C. The time is on the y-axis and the temperature
is on the x-axis.
D. The temperature is on the y-axis and the time
is on the x-axis.
Answer: d
Explanation:
On edg