Answers
Related Questions
Equipment used for solar energy is usually not expensive.
True False
Answers
Answer:
False, hope this helps!
Explanation:
Have you ever eaten a coin?
Answers
Answer:
yes
Explanation:
bc i wanted to know how they taste btw they taste like metal not good 5/10
might try again but not recommended
my favorite one is a quarter probably
There is a 2 percent defect rate at a specific point in a production process. If an inspector is placed at this point, all the defects can be detected and eliminated. The inspector would cost $10 per hour and could inspect units in the process at the current production rate of 48 per hour.
If no inspector is hired and defects are allowed to pass this point, there is a cost of $11 per defective unit to correct the defects later on.
Assume that the line will operate at the same rate (i.e., the current production rate) regardless of whether the inspector is hired or not.
a. If an inspector is hired, what will be the inspection cost per unit? (Round your answer to 3 decimal places.)
Inspection cost per unit _____________$
b. If an inspector is not hired, what will be the defective cost per unit? (Round your answer to 3 decimal places.)
Defective cost per unit _____________$
c. Should an inspector be hired based on costs alone?
Answers
Answer:
A) $0.208 per unit
B) $0.220 per unit
C) An inspector should be hired
Explanation:
percentage of defect rate = 2% = 0.02
cost of inspector = $10 per hour
production rate = 48 per hour
cost of not hiring an inspector = $11
A) Determine the inspection cost per unit if an inspector is hired
= cost of inspector / production rate
= 10 / 48 = $0.208 per unit
B) Determine the defective cost per unit if an Inspector is not hired
= cost of not hiring an inspector * percentage of defect rate
= 11 * 0.02
= $0.220 per unit
C) Inspection cost < defective cost i.e. $0.208 < $0.220 hence an inspector should be hired
What happens when sodium and chlorine react to make table salt
Please help
Answers
Round off the following measurements to two significant figures. Write the answers in scientific notation. a. 6310 m b. 125.00 Kg c. 6906 km d. 0.0828 m
need steps and formela
Answers
Explanation:
a. 6310 m
Two significant numbers means it must have only 2 digits. The first two digits are 6 and 3. The next number 1 is not up to 5 hence it would be round off to zero.
Two s.f = 6300
Converting it to scientific notation means it must be expressed by a number between 1 and 10, multiplied by a power of 10.
6.3 x 10^3
b. 125.00 Kg
Two significant numbers means it must have only 2 digits. The first two digits are 1 and 2. The next number 5 is up to 5 hence it would be round up to one.
Two s.f = 130.00
Converting it to scientific notation means it must be expressed by a number between 1 and 10, multiplied by a power of 10.
Scientific notation = 1.3 x 10^2
c. 6906 km
Two significant numbers means it must have only 2 digits. The first two digits are 6 and 9. The next number 0 is not up to 5 hence it would be round up to zero.
Two s.f = 6900
Converting it to scientific notation means it must be expressed by a number between 1 and 10, multiplied by a power of 10.
Scientific notation = 6.9 x 10^3
d. 0.0828 m
Two significant numbers means it must have only 2 digits. The first two digits(excluding zero) are 8 and 2 . The next number 8 is up to 5 hence it would be round up to one.
Two s.f = 0.083
Converting it to scientific notation means it must be expressed by a number between 1 and 10, multiplied by a power of 10.
Scientific notation = 8.3 x 10^-2
How many moles of SO3 are produced when 1.5 mol of O2 react with SO2?
Answers
Answer:
3 mole O2
Explanation:
Need balanced equation first: O2 + 2SO2 --> 2SO3
assuming SO2 is in excess,
1.5 mol O2 (2moles SO3/1mole O2) = 3 mole O2
How many moles of "02" are in a 192g sample of O2? *
1
2
3
4
5
6
7
Answers
Answer: The number of moles of [tex]O_2[/tex] are 6.
Explanation:
According to avogadro's law, 1 mole of every substance occupies 22.4 L at STP and contains avogadro's number [tex]6.023\times 10^{23}[/tex] of particles.
To calculate the moles, we use the equation:
[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text {Molar mass}}[/tex]
Given mass = 192 g
Molar mass = 32 g/mol
[tex]\text{Number of moles}=\frac{192g}{32g/mol}=6mol[/tex]
The number of moles of [tex]O_2[/tex] are 6.
7. Consider an element with 2
electrons on the 1st shell and 4
electrons on the 2nd shell. What
element is likely to have that Bohr
model?
Answers
Answer:
Carbon (C)
Explanation:
The electron configuration of Carbon is 2-4.
A can of butane with a pressure of 2 atm at 283k has its pressure increased to a new pressure of 5 atm. What is the temperature of the new container?
Answers
Answer:
New temperature T2 = 707.5 K (Approx.)
Explanation:
Given:
Old pressure P1 = 2 atm
Old temperature T1 = 283 K
New Pressure P2 = 5 atm
Find:
New temperature T2
Computation:
Using Gay-Lussac law;
P1 / T1 = P2 / T2
So,
2 / 283 = 5 / T2
New temperature T2 = 707.5 K (Approx.)
HELP!!!! Which of the following substances is a major component in acid rain?
A) KOH
B) NH3
C) SO2
D) NaOH
Answers
SO2 is known as sulfur dioxide.
The below information about acid rain and SO2’s involvement is from epa.gov:
“Acid rain results when sulfur dioxide (SO2) and nitrogen oxides (NOX) are emitted into the atmosphere and transported by wind and air currents. The SO2 and NOX react with water, oxygen and other chemicals to form sulfuric and nitric acids. These then mix with water and other materials before falling to the ground.”
Hope this helps!
Answer:
(C) SO2.
SO2 is known as sulfur dioxide.
The below information about acid rain and SO2’s involvement is from epa.gov:
“Acid rain results when sulfur dioxide (SO2) and nitrogen oxides (NOX) are emitted into the atmosphere and transported by wind and air currents. The SO2 and NOX react with water, oxygen and other chemicals to form sulfuric and nitric acids. These then mix with water and other materials before falling to the ground.”
Explanation:
9. The times of first sprinkler activation (in seconds) for a series of tests of fire-prevention sprinkler systems that use aqueous film-forming foam is as follows. The system has been designed so that the true average activation time is supposed to be at most 25 seconds. Does the data indicate the design specifications have not been met
Answers
This question is incomplete, the complete question is;
The times of first sprinkler activation (in seconds) for a series of tests of fire-prevention sprinkler systems that use aqueous film-forming foam is as follows; 27 41 22 27 23 35 30 33 24 27 28 22 24
( see " use of AFFF in sprinkler systems," Fire technology, 1975: 5)
The system has been designed so that the true average activation time is supposed to be at most 25 seconds.
Does the data indicate the design specifications have not been met?
Test the relevant hypothesis at significance level 0.05 using the P-value approach
Answer:
since p-value (0.042299) is lesser than the level of significance ( 0.05)
We Reject Null Hypothesis
Hence, There is no sufficient evidence that the true average activation time is at most 25 seconds
Explanation:
Given the data in the question;
lets consider Null and Alternative hypothesis;
Null hypothesis H₀ : There is sufficient evidence that the true average activation time is at most 25 seconds
Alternative hypothesis H₁ : There is no sufficient evidence that the true average activation time is at most 25 seconds
i.e
Null hypothesis H₀ : μ ≤ 25
Alternative hypothesis H₁ : μ > 25
level of significance σ = 0.05
first we determine the sample mean;
[tex]x^{bar}[/tex] = [tex]\frac{1}{n}[/tex]∑[tex]x_{i}[/tex]
where n is sample size and ∑[tex]x_{i}[/tex] is summation of all the sample;
= [tex]\frac{1}{13}[/tex]( 27 + 41 + 22 + 27 + 23 + 35 + 30 + 33 + 24 + 27 + 28 + 22 + 24 )
= [tex]\frac{1}{13}[/tex]( 363
sample mean [tex]x^{bar}[/tex] = 27.9231
next we find the standard deviation
s = √( [tex]\frac{1}{n-1}[/tex]∑([tex]x_{i}-x^{bar}[/tex])²
x ([tex]x_{i}-x^{bar}[/tex]) ([tex]x_{i}-x^{bar}[/tex])²
27 -0.9231 0.8521
41 13.0769 171.0053
22 -5.9231 35.0831
27 -0.9231 0.8521
23 -4.9231 24.2369
35 7.0769 50.0825
30 2.0769 4.3135
33 5.0769 25.7749
24 -3.9231 15.3907
27 -0.9231 0.8521
28 0.0769 0.0059
22 -5.9231 35.0831
24 -3.9231 15.3907
sum 378.9229
so ∑([tex]x_{i}-x^{bar}[/tex])² = 378.9229
∴
s = √( [tex]\frac{1}{13-1}[/tex] ×378.9229 )
s = √31.5769
standard deviation s = 5.6193
now, the Test statistics
t = ( [tex]x^{bar}[/tex] - μ ) / [tex]\frac{s}{\sqrt{n} }[/tex]
we substitute
t = ( 27.9231 - 25 ) / [tex]\frac{5.6193}{\sqrt{13} }[/tex]
t = 2.9231 / 1.5585
t = 1.88
now degree of freedom df = n - 1 = 13 - 1 = 12
next we calculate p-value
p-value = 0.042299 ( using Execl's ( = TDIST(1.88,12,1)))
Here x=1.88, df=12, one tail
now we compare the p-value with the level of significance
since p-value (0.042299) is lesser than the level of significance ( 0.05)
We Reject Null Hypothesis
Hence, There is no sufficient evidence that the true average activation time is at most 25 seconds
When lava cools outside the Earth, ____ igneous rocks are formed
Answers
Answer:The rock forms large crystals
Explanation:
15 points AND BRAINLIEST!!
At what Celsius temperature will Neon have a mass of 0.02 kg and a pressure of 6.43 atm in 2.5 L
container
Answers
Answer:
[tex]T=-75.59\°C[/tex]
Explanation:
Hello!
In this case, since we can treat neon as an ideal gas, it is possible for us to use the following equation:
[tex]PV=nRT[/tex]
Whereas the temperature is out unknown, so we proceed as follows:
[tex]T=\frac{PV}{nR}[/tex]
However, we need the moles of neon in 0.02 kg as shown below:
[tex]n=0.02kg*\frac{1000g}{1kg}*\frac{1mol}{20.17g} =0.992mol[/tex]
Thus, we obtain the following temperature in Kelvins:
[tex]T=\frac{6.43atm*2.5L}{0.992mol*0.08206\frac{atm*L}{mol*K}} \\\\T=197.56K[/tex]
Therefore, in degree Celsius it is:
[tex]T=197.56-273.15\\\\T=-75.59\°C[/tex]
Best regards!
Ionic compounds form between two metals true
Answers
Answer (TL;DR):
False, ionic compounds form between a metal and a nonmetal. This is because metals are looking to lose electrons to get a full outer shell while nonmetals are looking to gain electrons to get a full outer shell.
Explanation:
Atoms have a full outer shell when their outermost shell holds the maximum number of electrons. For example, if the outermost shell is the first shell of the atom, it can hold up to 2 atoms. When this shell holds 2 atoms, it is considered full. If the outermost shell is the second shell of the atom, it can hold up to 8 atoms. When this shell holds 8 atoms, it is considered full. This can also be referred to as an atom "gaining a complete octet." The reason that atoms want a complete octet is to become stable and less reactive.
Let's say an atom with 3 shells has only 1 electron on the third shell. It doesn't have a complete octet and it wants to gain one. The third shell can hold up to 8 electrons. So, to gain a complete octet, the atom can either gain 7 electrons or just lose the 1 that it already has, which is the easier option. This is the case with metals and the opposite goes for nonmetals.
Because metals want to lose electrons and nonmetals want to gain electrons, they form compounds with each other.
I hope this helps!
Composition of Dry AirGas Percent by Volume (%)Nitrogen (N2) 78Oxygen (O2) 21Argon (Ar) 0.9Carbon dioxide (CO2) 0.04 What volume of air contains 12.3 g of oxygen gas at 273 K and 1.00 atm
Answers
Answer:
40.95 L
Explanation:
We'll begin by calculating the number of mole in 12.3 g of O₂. This can be obtained as follow:
Mass of O₂ = 12.3 g
Molar mass of O₂ = 16 × 2 = 32 g/mol
Mole of O₂ =?
Mole = mass / Molar mass
Mole of O₂ = 12.3 / 32
Mole of O₂ = 0.384 mole
Next, we shall determine the volume occupied by 0.384 mole of O₂. This can be obtained as follow:
Number of mole (n) of O₂ = 0.384 mole
Pressure (P) = 1 atm
Temperature (T) = 273 K
Gas constant (R) = 0.0821 atm.L/Kmol
Volume (V) of O₂ =?
PV = nRT
1 × V = 0.384 × 0.0821 × 273
V = 0.384 × 0.0821 × 273
V = 8.6 L
Thus, the volume of O₂ is 8.6 L
Finally, we shall determine the volume of air that contains 8.6 L of O₂. This can be obtained as follow:
Volume of O₂ = 8.6 L
Percentage of O₂ in air = 21%
Volume of air =?
Percentage of O₂ = Vol of O₂ / Vol of air × 100
21% = 8.6 / Vol of air
21 / 100 = 8.6 / Vol of air
Cross multiply
21 × Vol of air = 100 × 8.6
21 × Vol of air = 860
Divide both side by 21
Volume of air = 860 / 21
Volume of air = 40.95 L
Therefore, the volume of air is 40.95 L.
DIRECTION: Supply the missing information about the scientist listed in the graphic
organizer.
HELP ME PLEASSEEEE
I'll give you brainliest I promise
Answers
Answer:
The missing information or their role in the discovery of the cell is as follows:
Robert Hooke: He was the first scientist to called cells to tiny box-like cavities he saw in cork and illustrated as cells.
A. Leeuwenhoek: he was a microscopist and microbiologist who used microscopes and observed many other living cells. He called animalcules to these single-cell living organisms later used to prove that cells are the fundamental unit of life.
Schwann and Schleiden: They presented the theory that suggested that the cells are basic building blocks of all living things.
Virchow: He observed that the cell dividing and come from pre-existing cells.
Water from a riverbed carries sediment downstream. The water pressure cuts deep into the riverbed, creating a deep, narrow channel What has happened? A A delta has formed . B Sand dunes are created. C A volcano has erupted . D A canyon has formed .
Answers
Answer:
A canyon has formed.
Explanation:
What causes lightning?
A. Build up of electric charges in the clouds
B. Flow of electric charges among clouds
C. Light energy created in the clouds
D. Reflection of light by the clouds
Answers
Answer:
B.
Explanation:
Not sure if this is correct if not sorry.
The change from a liquid to a solid is called
Answers
Answer:
A cat jk but for real (It's called Freezing and I feel like explaining it)
Explanation:
Freezing is a process where a liquid changes to a solid by cooling.
If water (liquid state) is cooled, it changes to ice (solid-state). This change is called FREEZING. The temperature at which this occurs is called the freezing point (fp) of the substance.
Answer:
Freezing phase transition
Explanation:
Freezing is a phase transition in which a liquid turns into a solid when its temperature is lowered to its freezing point.Freezing, or solidification, is a phase transition in which a liquid turns into a solid when its temperature is lowered to or below its freezing point. All known liquids, except helium, freeze when the temperature is low enough.
(hope this helps can i plz have brainlist :D hehe)
How did Dmitri Mendeleev arrange the periodic law?
a. Each set of elements was arranged in special columns based on their mass.
b. Each set of elements was arranged in special columns based on their diameter.
c. Each set of elements was arranged in special periods based on their qualities.
d. Each set of elements was arranged in alphabetical order.
Answers
Answer:
a. Each set of elements was arranged in special coloumns based on their mass.
Early chemists, known at the time as alchemists, had a difficult time understanding the Law of Conservation of Mass. Using the burning of wood as an example, what property of matter made this law difficult for early scientists to understand?
Answers
So, in other words, mass cannot be created nor destroyed.
In a burning log, the initial mass of the wood and the ashes that are left behind after it burns are different, which would seem to violate the law of conservation of mass.
The law of conservation of mass states that, for any isolated system, the mass can neither be created nor be destroyed
After burning a log, the remains that are left behind after it burns are lesser than what would initially seem. There is a difference in mass before the burning of the log after the burning of the log. This seems like a violation of the law of conservation of mass, which would have made it difficult for early chemists to understand it. But if we consider the surroundings as a system then we can see that the mass that is lost in burning is actually converted into smoke and energy or forming other forms of substances. Then considering the whole system we can see that the mass and energy are conserved and interrelated.learn more about conservation of mass and energy:
https://brainly.com/question/13971039
1. Hydrogen, Helium, Lithium?
Answers
Answer:
what happened to it, have the gone extinct
there is no such thing as a universal solvent- explain? I’ll mark brainiest!!!
Answers
Answer:
A true universal solvent does not exist. Although water is considered to be a the "universal solvent" it only dissolves other polar molecules. It does not dissolve nonpolar molecules, including organic compounds such as fats and oils. It is only called so because it can dissolve many more than other liquids.
A compound of nitrogen and oxygen is 30.46% by mass N and 69.54% by mass O.
The molar mass if the compound was determined to be 92 g/mol.
a. What is the empirical formula of the compound?
b. What is the molecular formula of the compound?
Answers
Answer: characteristic molar mass of an element is simply the atomic mass in g/mol. However, molar mass can also be calculated by multiplying the atomic mass in amu by the molar mass constant (1 g/mol).
Explanation:
o calculate the molar mass of a compound with multiple atoms, sum all the atomic mass of the constituent atoms. so the answer to your question is B
An unknown compound contains only C , H , and O . Combustion of 5.90 g of this compound produced 11.8 g CO2 and 4.83 g H2O . What is the empirical formula of the unknown compound
Answers
Answer:
C₂H₄O
Explanation:
In a compound that contains Cabon, hydrogen and oxygen, the combustion produce CO₂ from the carbon, and H₂O from the hydrogens. Using the mass of the products we can solve the moles of Carbon and hydrogen. The empirical formula is the simplest whole-number of atoms present in a molecule.
Moles CO₂ = Moles C:
11.8g CO₂ * (1mol / 44g) = 0.268 moles CO₂ = 0.268 moles C * (12g/mol) =
3.216g C
Moles H₂O = 1/2 moles H:
4.83g H₂O * (1mol / 18g) = 0.268 moles H₂O * (2 mol H / 1 mol H₂O) =
0.537 mol H * (1g/mol) = 0.537g H
Mass O to find moles O:
5.90g Sample - 3.216g C - 0.537g H = 2.147g O * (1mol / 16g) = 0.134 moles O
Ratio of atoms -Dividing in 0.134 moles-:
C = 0.268mol C / 0.134 mol O = 2
H = 0.537mol H / 0.134 mol O = 4
O = 0.134mol O / 0.134 mol O = 1
Empirical formula is:
C₂H₄OWhat two methods are used for determining the age of rocks and fossils?
Relative and Absolute Dating
Carbon and Water Dating
Absolute and Resolute Dating
Relative and Absent Dating
Answers
Explanation:
first one because absolute dating is a thing for rock layers
solve this .......,..,.,.,..,.,,.,.,.,.,.,.,.,.,..,.,.,.,.z.,.,.,.,..,.,.,.,.,,.,.,.,
Answers
Answer: Molecular formula of copper (II) bromide is [tex]CuBr_2[/tex]
Molecular formula of aluminium (III) nitrate is [tex]Al(NO_3)_3[/tex]
Molecular formula of calcium (II) phosphate is [tex]Ca_3(PO_4)_2[/tex]
Molecular formula of iron (III) sulphide is [tex]Fe_2S_3[/tex]
Molecular formula of mercury (II) chloride is [tex]HgCl_2[/tex]
Molecular formula of magnesium (II) acetate is [tex](CH_3COO)_2Mg[/tex]
Explanation:
The name of the ionic compounds is written by writing the name of the cation first followed by its oxidation state in round brackets and then the name of the anion is written without any suffix. Thus the cation is written first followed by the oxidation state and then the anion.
For formation of a neutral ionic compound, the charges on cation and anion must be balanced. Thus they combine and their oxidation states are exchanged and written in simplest whole number ratios to give neutral compound.
Molecular formula of copper (II) bromide is [tex]CuBr_2[/tex]
Molecular formula of aluminium (III) nitrate is [tex]Al(NO_3)_3[/tex]
Molecular formula of calcium (II) phosphate is [tex]Ca_3(PO_4)_2[/tex]
Molecular formula of iron (III) sulphide is [tex]Fe_2S_3[/tex]
Molecular formula of mercury (II) chloride is [tex]HgCl_2[/tex]
Molecular formula of magnesium (II) acetate is [tex](CH_3COO)_2Mg[/tex]
what are the lewis structures for [SrCN]-
Answers
Which is true about relative dating?
Potassium –Argon dating is used on very old rocks and minerals.
Carbon-14 dating is used on rocks and minerals that are relatively young
Relative dating uses the half-life of isotopes to get the exact age of a rock or mineral
The law of superposition is used to determine a rocks relative age.
Answers
it's the last one because it's depended on the rock layers
Answer:
The law of superposition is used to determine a rocks relative age.
I need help please please
Answers
Answer:
B should be the answer, and ur low-key valid lol
Explanation: