what are the lewis structures for [SrCN]-
1. Hydrogen, Helium, Lithium?
Answer:
what happened to it, have the gone extinct
Ice floats on the surface of water because ice is less dense than liquid water
true or false?
Answer:
yes it is true.
Ice floats on the surface of water because ice is less dense than liquid water
Explanation:
Ionic compounds form between two metals true
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!
DIRECTION: Supply the missing information about the scientist listed in the graphic
organizer.
HELP ME PLEASSEEEE
I'll give you brainliest I promise
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.
I need help please please
Answer:
B should be the answer, and ur low-key valid lol
Explanation:
What 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
Explanation:
first one because absolute dating is a thing for rock layers
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
Answer:
B.
Explanation:
Not sure if this is correct if not sorry.
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
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:
C₂H₄OHELP!!!! Which of the following substances is a major component in acid rain?
A) KOH
B) NH3
C) SO2
D) NaOH
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:
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 .
Answer:
A canyon has formed.
Explanation:
Can someone help with these questions please???
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?
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
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?
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 is its molar concentration?
Answer:
The correct answer is - the number of moles of solute per liter of solution.
Explanation:
The molar concentration is also known as molarity which is the amount of concentration of a solute is in a chemical solution is the number of moles of solute per unit volume of solution. It is represented as M and can be calculated by:
M = n/v
Where n is the number of moles of the solute and,
v is the volume of solution (in liters normally)
It is worldwide used measurment for the concentration.
Richard sketched models of two different neutral isotopes of oxygen. If the
isotope models are accurate, which statement might be true? (Refer to the
periodic table if necessary.)
A. One shows 7 protons, and one shows 9.
B. One shows 8 neutrons, and one shows 9.
C. One shows 8 electrons, and one shows 9.
D. One shows 8 protons, and one shows 7.
Answer:
its b
Explanation:
just did the test on A P E X
If the isotope models are accurate, One shows 8 neutrons, and one shows 9. Therefore, the correct option is option B.
What is isotope?A chemical element's isotope is one of more than one species of atoms that share the same atomic number, spot on the periodic table, and almost identical chemical activity, but differ in atomic mass and physical characteristics. There are a number of isotopes for each chemical element.
The first step in identifying and labelling an atom is to count the protons within its nucleus. Usually, this nuclear number is denoted by the letter Z. The fact that all atoms possessing the same number of electrons have essentially equal chemical characteristics lends the atomic number its enormous significance. If the isotope models are accurate, One shows 8 neutrons, and one shows 9.
Therefore, the correct option is option B. If the isotope models are accurate, One shows 8 neutrons, and one shows 9.
To know more about isotope, here:
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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
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
Determine the mass of AgCl(s) produced when 0.91 g of AgNO3 in an aqueous solution reacts with excess NaCl aqueous solution as shown below: AgNO3(aq) + NaCl(aq) → AgCl(s) + NaNO3(aq) i Respond with the correct number of significant figures in scientific notation (Use E notation and only 1 digit before decimal e.g. 2.5E5 for 2.5 x 10")
Answer:
0.77 g
Explanation:
Step 1: Write the balanced equation
AgNO₃(aq) + NaCl(aq) → AgCl(s) + NaNO₃(aq)
Step 2: Calculate the moles corresponding to 0.91 g of AgNO₃
The molar mass of AgNO₃ is 169.87 g/mol.
0.91 g × 1 mol/169.87 g = 5.4 × 10⁻³ mol
Step 3: Calculate the moles of AgCl produced from 5.4 × 10⁻³ moles of AgNO₃
The molar ratio of AgNO₃ to AgCl is 1:1. The moles of AgCl produced are 1/1 × 5.4 × 10⁻³ mol = 5.4 × 10⁻³ mol.
Step 4: Calculate the mass corresponding to 5.4 × 10⁻³ moles of AgCl
The molar mass of AgCl is 143.32 g/mol.
5.4 × 10⁻³ mol × 143.32 g/mol = 0.77 g
The change from a liquid to a solid is called
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)
10-kg of R-134a at 300 kPa fills a rigid container whose volume is 14 L. Determine the temperature and total enthalpy in the container. The container is now heated until the pressure is 600 kPa. Determine the temperature and total enthalpy when the heating is completed.
Answer:
Temperature = 0.605°C
Total enthalpy at 300kpa = 545.2 kJ
Total enthalpy at 600kpa = 846.45 kJ.
Explanation:
Checking the table for 134a pressure table. It is given that the specific volume of saturated liquid and the specific volume of the saturated vapor of 280kpa is 0.0007699 m^3/kg and 0.072352 m^3/kg respectively.
Also, the specific volume of saturated liquid and the specific volume of the saturated vapor of 320kpa is 0.0007772 m^3/kg and 0.063604 m^3/kg respectively.
The first thing to do is to determine the value for the specific volume of saturated liquid.
At 300 kpa, the specific volume of saturated liquid,n is given below as;
300 - 280/ 320 - 280 = (n - 0.0007699)/ 0.0007772 - 0.0007699.
Therefore, n = specific volume of saturated liquid = 0.0007735 m^3/kg.
300 - 280/ 320 - 280 = n - 0.072352/ (0.063604 - 0.072352).
n = 0.0679 m^3/kg.
The second thing to do is to determine the value of the specific volume.
Specific volume = 14 × 10^-3/ 10 = 0.0014 m^3/kg.
Determine the enthalpy of the mixture,b(I). This is given below as;
300 - 280/ 320 - 280 = b(I) - 199.54/ (196.7 - 199.54).
b(I) = 198.125 kJ/Kg.
Hence, b = [ 300 - 280/ 320 - 280 = j - 50.18 / 55.16 - 50.18] + [ ( 0.0014 - 0.00077735) / 0.067978 - 0.00077735] × 198.125.
b = 54.517 KJ/Kg.
Total enthalpy = 10 × 54.517 = 545.17 kJ.
Temperature can be Determine as below;
300 - 280/ 320 - 280 = T + 1.25 / 2.46 - 1.25.
Temperature = 0.605°C.
Hence, at 600kpa, the total enthalpy = [81.51 + ( 0.0014 - 0.0008199/ 0.034295 - 0.0008199) × 180.90] × 10
Total enthalpy at 600kpa = 846.45 kJ.
Equipment used for solar energy is usually not expensive.
True False
Answer:
False, hope this helps!
Explanation:
1. How would you describe what red cabbage juice is?*
(1 Point)
Acid
Neutral
Alkali
Indicator
Salt
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?
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:
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How many moles of "02" are in a 192g sample of O2? *
1
2
3
4
5
6
7
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.
Calcium and titanium atoms have the same mass
Answer:
these elements do not have the same masses.
what process formed slate
Answer:
Explanation:
Slate is a fine-grained, foliated metamorphic rock that is created by the alteration of shale or mudstone by low-grade regional metamorphism. It is popular for a wide variety of uses such as roofing, flooring, and flagging because of its durability and attractive appearance.
Answer:
Deep within the Earth's crust rocks can be put under huge pressures and temperatures are very high. These conditions can cause the minerals in the rock to change. This process is called metamorphism. Limestone can change into marble, shale and mudstones into slate, and igneous rocks like granite can turn into gneiss.
Explanation:
Slate is a fine-grained, foliated metamorphic rock that is created by the alteration of shale or mudstone by low-grade regional metamorphism. It is popular for a wide variety of uses such as roofing, flooring, and flagging because of its durability and attractive appearance.
What happens when sodium and chlorine react to make table salt
Please help
When lava cools outside the Earth, ____ igneous rocks are formed
Answer:The rock forms large crystals
Explanation:
Can some one help I'm lost iam being timed:( Show using two conversion factors how you would convert from 0.020 kg into mg
Answer:
20000 Mg
Explanation:
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.
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.