housefly
Explanation:
Because it one of the affective vector of disease carrier and it always roam towards wastes and dirty materials likely to get attracted . And it carries contagious disease from hospitals , infected patients , etc .
1) The percentage of oxygen in dry air is _______
A. 0.1
B. 1.0
C. 21
D. 79
2) The composition of the Earth’s earliest atmosphere was different to that of the present atmosphere. Which of these gases was present in large amounts in the Earth’s earliest atmosphere?
A. Oxygen
B. Carbon dioxide
C. Ammonia
D. Nitrogen
Answer:
1) The percentage of oxygen in dry air is _______
C. 21
2) The composition of the Earth’s earliest atmosphere was different to that of the present atmosphere. Which of these gases was present in large amounts in the Earth’s earliest atmosphere?
B. CARBON DIOXIDE
Hope it helps
have a nice day
Answer: The percentage of oxygen in dry air is . 21
Explanation: Ammonia gases was present in large amounts in the easth7s earliest atmosphere
Hope it will help you
Two magnets are stuck together. What might you have to do to get them to separate?
Explanation:
The easiest method to separating magnets is to slide them apart. When separating magnets keep in mind shear force. Magnets are measured on pull strength, so are up to five times easier to move if they are pushed apart instead of pulled apart. Small magnets slide relatively easily, even without spacers.
Firmly slide them away from each other and far enough apart so that they don't hop back together. Neodymium magnets are quite strong.
What are properties of a magnet?The properties of the magnet are:
Magnets will attract ferromagnetic.Like poles of the magnet repel each other and unlike poles bait each otherThe poles of the magnet are in the team.Thus, slide them away from each other and far enough apart so that they don't hop back together.
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Oxygen is a diatomic element.why give reason.
Answer:
Diatomic molecules contain two atoms that are chemically bonded. If the two atoms are identical, as in, for example, the oxygen molecule (O2), they compose a homonuclear diatomic molecule, while if the atoms are different, as in the carbon monoxide molecule (CO), they make up…
Explanation:
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How many bonds can a carbon atom form?
O A. 1
B. 2
C. 4
O D. 3
If a gas is pumped from a smaller container to a container that is twice the size, and its pressure is kept the same, then what happens to the temperature of the gas?
Answer: If a gas is pumped from a smaller container to a container that is twice the size, and its pressure is kept the same, then temperature of the gas increases twice.
Explanation:
Charles law states that at constant pressure, the volume of a gas is directly proportional to the temperature.
That is, [tex]V \propto T[/tex].
So, when a gas is pumped from a smaller container to a container that is twice the size shows that volume is increasing by 2 times and its pressure is kept the same.
Therefore,
[tex]2V \propto 2T[/tex]
This means that the temperature of the gas will also become twice its initial temperature.
Thus, we can conclude that if a gas is pumped from a smaller container to a container that is twice the size, and its pressure is kept the same, then temperature of the gas increases twice.
What is the mass of NaCl required to make 140 grams of a 12% solution of NaCl in water?
12 grams
14 grams
17 grams
18 grams
Answer: The mass of NaCl required to make 140 grams of a 12% solution of NaCl in water is 17 g.
Explanation:
Given: Mass of solution = 140 g
Mass percent = 12%
Formula used to calculate grams of solute are as follows.
[tex]Grams of solute = \frac{grams of solution \times mass percent}{100 percent}[/tex]
Substitute the values into above formula as follows.
[tex]Grams of solute = \frac{grams of solution \times mass percent}{100 percent}\\= \frac{140 g \times 12 percent}{100 percent}\\= 16.8 g\\= 17 g[/tex]
Thus, we can conclude that the mass of NaCl required to make 140 grams of a 12% solution of NaCl in water is 17 g.
Considering the definition of percentage by mass, the correct answer is the third option: 17 grams of NaCl is required to make 140 grams of a 12% solution of NaCl in water.
The Percentage Composition is a measure of the amount of mass that an element occupies in a compound and indicates the percentage by mass of each element that is part of a compound.
This is, the percentage by mass expresses the concentration and indicates the amount of mass of solute present in 100 grams of solution.
In other words, the percentage by mass of a component of the solution is defined as the ratio of the mass of the solute to the mass of the solution, expressed as a percentage.
The percentage by mass is calculated as the mass of the solute divided by the mass of the solution, the result of which is multiplied by 100 to give a percentage. This is:
[tex]percentage by mass=\frac{mass of solute}{mass of solution}x100[/tex]
In this case, you know:
percentage by mass= 12%mass of solute= ?mass of solution= 140 gramsReplacing:
[tex]12=\frac{mass of solute}{140 grams}x100[/tex]
Solving:
mass of solute= [tex]\frac{12 x 140 grams}{100}[/tex]
mass of solute= 16.8 grams ≅ 17 grams
Finally, the correct answer is the third option: 17 grams of NaCl is required to make 140 grams of a 12% solution of NaCl in water.
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why atoms of magnet differ from normal atoms?
Copied answers ❌❌❌
Answer:
The magnetic field of an atom, say H (one electron revolving around a proton) is composed of two separate contributions: an orbital magnetic moment and a spin magnetic moment. We get magnetic moments because of electromagnetic induction associated with each type of electron motion. The electron revolving around the proton with a certain angular momentum is related to the associated orbital magnetic moment (and, yes, we model it as a wire loop with current expressed in terms of the orbital velocity). This can be calculated using elementary mechanics. The spin magnetic moment is a little trickier because it is caused by the intrinsic spin of the electron which is a quantum phenomenon; therefore, this spin magnetic moment can only be calculated using quantum mechanics. In the end, we get a certain net magnetic moment associated with this motion of the electron in an atom. It is important to notice that this atom acts as a magnetic dipole (remember, as of yet, magnetic monopoles don't exist!).
If we take a bulk magnet like you might have on your fridge, it would be composed of atoms. Each atom operates as a magnetic dipole, but due to internal atomic structures, the atoms actually align themselves into separate magnetic domains, each with a net magnetic moment (caused my individually adding up those atomic dipole moments). In a common magnet (ferromagnet), these domains all point the same direction and stay that way, creating a permanent bulk magnetic dipole.
So in a way, there is no difference between the magnetic field of an atom and that of a magnet because one is simply a sum of the other, making both magnetic dipoles. Of course, here we see that there's nothing that fundamental about the magnetic force. In reality, the magnetic force is a relativistic effect caused by the movement of a charged particle, making electricity (i.e. charge) the underlying property at work here. Electromagnetic induction is really a shortcut to understand the magnetic force without worrying about relativistic mechanics. If we were to discover magnetic monopoles (i.e. "magnetic" charge), this would re-write a lot that we know about electromagnetism because we couldn't label all magnetic forces as by-products of moving electric charge
A gas is put into a cosed container.
The container and the gas inside it are heated.
What will happen to the pressure inside the container?
Answer:
When gases in containers are heated, their molecules increase in average speed. This means that they exert a greater force when they collide with the container walls, and also collide with the walls more frequently. The gas is therefore under greater pressure when its temperature is higher.
The structure shown is an example of what kind of molecule?
A) Ether
B) Alkene
C) Polymer
D) Monomer
Answer:
i think its C polymer hope it helps
How many grams of ammonia can be produced from reacting a 450 L sample of nitrogen gas at a temperature of 450 K and a pressure of 300 atm?
Answer: The mass of ammonia is 124457.96 g which can be produced from reacting a 450 L sample of nitrogen gas at a temperature of 450 K and a pressure of 300 atm.
Explanation:
Given: Volume = 450 L
Temperature = 450 K
Pressure = 300 atm
The reaction equation is as follows.
[tex]N_{2} + 3H_{2} \rightarrow 2NH_{3}[/tex]
Here, 1 mole of nitrogen reacts to give 2 moles of ammonia.
From the given data, moles of nitrogen are calculated as follows.
PV = nRT
where,
P = pressure
V = volume
n = no. of moles
R = gas constant = 0.0821 L atm/mol K
T = temperature
Substitute the values into the above formula as follows.
[tex]PV = nRT\\300 atm \times 450 L = n \times 0.0821 L atm/mol K \times 450 K\\n = \frac{300 atm \times 450 L}{0.0821 L atm/mol K \times 450 K}\\= \frac{135000}{36.945}\\= 3654.08 mol[/tex]
For 3654.08 moles of nitrogen, the moles of ammonia produced is as follows.
[tex]2 \times 3654.08 mol\\= 7308.16 mol[/tex]
Therefore, mass of ammonia (molar mass = 17.03 g/mol) is calculated as follows.
[tex]Moles = \frac{mass}{molarmass}\\7308.16 mol = \frac{mass}{17.03 g/mol}\\mass = 124457.96 g[/tex]
Thus, we can conclude that the mass of ammonia is 124457.96 g which can be produced from reacting a 450 L sample of nitrogen gas at a temperature of 450 K and a pressure of 300 atm.
HELPPPPPPPP i accidentally pressed on c
Answer:
a
Explanation:
I'm not completely sure tho veary sorry if it's wrong
Answer:
the answer is C
Explanation:
as the yeast feeds on sugar and yields the ATP per glucose molecule and Carbon dioxide
The formal charge and P-O bond order in PO43- respectively are 0.6, -0.75 -0.75, 1.25 1.0, -0.75 1.25, -3 98.
Answer:
-0.75 , 1.25
Explanation:
Number of electrons present in valence shell,
P-O = 5 + 8 = 13
Number of electrons involved in bond formation,
13 - 3 = 10
Number of bonds in PO3 - 4ion = 102
Average P-O bond = 1.25
Average formal charge on Oxygen atom is -0.75
if drop a watermelon from the top of one of the tower dorms at CSU, and it takes 3.34 seconds to hit the ground, calculate how tall the building is in meters and then convert into feet.
Answer:
179.5 feet
Explanation:
54.718 m converted to 179.5 feet.
Please a little help in this I will really appreciate it
Answer:
b is your answer...........
Below are descriptions of different center voids of a solid fuel. Which design
shape will generate the most thrust?
A. A heart
OB. A circle
C. A triangle
O D. A tree with branches
B. A circle.
The center void shape that generates the most thrust in a solid fuel rocket is a circle.
What is Fuel?
Fuel is a substance that is used to produce heat or energy through combustion or other chemical reactions. It can be in the form of a solid, liquid, or gas and is typically used to power engines, generators, or heating systems. Examples of fuels include gasoline, diesel, natural gas, coal, wood, and propane. The choice of fuel depends on factors such as availability, cost, energy content, and environmental impact.
This is because a circular shape allows for the most efficient burning of the fuel, with the flame front moving evenly in all directions. Other shapes, such as a heart, triangle, or tree with branches, can cause uneven burning and may result in less thrust.
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Answer:
Explanation:
D.
tree with branches
A 20.0 mL solution of NaOH is neutralized with 24.1 mL of 0.200 M HBr. What is the concentration of the original NaOH solution
Answer:
0.241 M
Explanation:
We'll begin by writing the balanced equation for the reaction. This is given below:
HBr + NaOH —> NaBr + H₂O
From the balanced equation above,
The mole ratio of acid, HBr (nₐ) = 1
The mole ratio of base, NaOH (n₆) = 1
Finally, we shall determine the concentration of the NaOH solution. This can be obtained as follow:
Volume of base, NaOH (V₆) = 20 mL
Volume of acid, HBr (Vₐ) = 24.1 mL
Concentration of acid, HBr (Cₐ) = 0.2 M
Concentration of base, NaOH (C₆) =?
CₐVₐ / C₆V₆ = nₐ/n₆
0.2 × 24.1 / C₆ × 20 = 1/1
4.82 / C₆ × 20 = 1
Cross multiply
C₆ × 20 = 4.82
Divide both side by 20
C₆ = 4.82 / 20
C₆ = 0.241 M
Therefore, the concentration of the NaOH solution is 0.241 M
Can someone please do a True or false for these PLEASE
Answer:
true
false
false
true
false
true
true
false
false
true
true
How many ATOMS of boron are present in 3.61 grams of boron trifluoride ?
Answer:
To determine the number of atoms of Boron that are present within 3.61 grams of Boron Trifluoride, it would be best to convert the grams to moles of the compound and then after that use the Avogadro's number to determine the number of molecules and then use the 1 to 3 ratio to determine the total number of Boron atoms.
WHAT IS PHOTOSYNTHESIS??
Answer:
the process by which green plants and some other organisms use sunlight to synthesize nutrients from carbon dioxide and water. Photosynthesis in plants generally involves the green pigment chlorophyll and generates oxygen as a by-product.
Answer:
the process by which green plants and some other organisms use sunlight to synthesize nutrients from carbon dioxide and water. Photosynthesis in plants generally involves the green pigment chlorophyll and generates oxygen as a by-product.
aseous methane will react with gaseous oxygen to produce gaseous carbon dioxide and gaseous water . Suppose 5.5 g of methane is mixed with 13.9 g of oxygen. Calculate the maximum mass of carbon dioxide that could be produced by the chemical reaction. Round your answer to significant digits.
Answer:
There is 9.6 grams of CO2 produced
Explanation:
Step 1: Data given
Mass of methane = 5.50 grams
Molar mass of methane = 16.04 g/mol
Mass of oxygen = 13.9 grams
Molar mass of oxygen = 32.0 g/mol
Step 2: The reaction
CH4(g) + 2O2(g) → CO2(g) + 2H2O(g)
Step 3: Calculate number of moles
Moles = mass / molar mass
Moles methane = 5.50 grams / 16.04 g/mol
Moles methane = 0.343 moles
Moles oxygen = 13.9 grams / 32.0 g/mol
Moles oxygen = 0.434 moles
For 1 mol CH4 we need 2 moles O2 to produce 1 mol CO2 and 2 moles H2O
O2 is the limiting reactant. It will completely react (0.434 moles).
There will react 0.434/2 = 0.217 moles CH4
There will remain 0.343-0.217 = 0.126 moles CH4
There will be produced 0.434 moles of H2O and
0.434/2 =0.217 moles of CO2
Step 4: Calculate mass of products
Mass = moles * molar mass
Mass CO2 = 0.217 moles ¨44.01 g/mol
Mass CO2 = 9.6 grams
Mass H2O = 0.434 moles * 18.02
Mass H2O = 7.8 grams
How long would it take Jesse, with an acceleration of -2.50 m/s², to bring his bicycle, with an initial velocity of 13.5 m/s, to a complete stop?
Answer:
i am so sorry. i do not have a answer but i am trying to find questioms i can answer
Una muestra de S2 (g) se coloca en un recipiente rígido vacío a 800 K y ésta ejerce una presión inicial de 0,92 atm, luego se combina para formar S8 (g) mediante la reacción: S2 (g) ⇆ S8 (g) Una vez alcanzado el equilibrio, la presión parcial de S2 (g) ha disminuido a 0,18 atm. Calcule Kp para la reacción a esta temperatura
Answer:g
Explanation:
What pollutants can contribute to acid precipitation and how are these pollutants generated?
Answer:
Acid rain is caused by a chemical reaction that begins when compounds like sulfur dioxide and nitrogen oxides are released into the air. These substances can rise very high into the atmosphere, where they mix and react with water, oxygen, and other chemicals to form more acidic pollutants, known as acid rain.
hope it helps
stay safe healthy and happy...Sulfur dioxide and nitrogen oxides can contribute to acid precipitation.
What are pollutants?A pollutant is a chemical or biological substance which harms water, air, or land quality.
Acid rain is caused by a chemical reaction that begins when compounds like sulfur dioxide and nitrogen oxides are released into the air. These substances can rise very high into the atmosphere, where they mix and react with water, oxygen, and other chemicals to form more acidic pollutants, known as acid rain.
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help sdfghrthfbfdve aahhhhhhhh
In which of the following will the density increase?
Group of answer choices
An iron bar is heated.
A lead weight is moved from sea level to the top of a high mountain.
A sample of water is frozen.
A diamond is submerged in water.
A sample of chlorine gas is compressed.
Which describes the difference between a claim and a scientific claim?
Claims are based more on truth than scientific claims are.
Anyone can make a claim, but a scientific claim is backed by experimental evidence.
Claims are based on evidence and scientific claims are made by scientists.
Controlled experiments are used in claims, while scientific claims use multiple trials.
Answer:
B. Anyone can make a claim, but a scientific claim is backed by experimental evidence.
<3 Have a nice day!!
Answer:
the awnser is B i got it right
Explanation:
Select the structure that corresponds
to the name:
decanoic acid
COOH
A.
B. CH3(CH2)7COOH
C. both
Answer:
b
Explanation:
Molecular formula of Decanoic Acid is C₁₀H₂₀O₂ therefore Option A is the right answer.
What is Decanoic Acid ?Decanoic Acid is a C10 , straight chain , saturated fatty acid . Its general formula is C₁₀H₂₀O₂ .
In the first option we can see a straight chain , saturated fatty acid and the molecular formula is also same as decanoic acid .
In second option the molecular formula is C₉H₁₈O₂ which is not same as Decanoic Acid.
Hence option A is the right answer.
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EN LA MINA DE CHUQUICATAMA SE EXPLOTA DIFERENTES METALES COMO SER EL COBRE , AL ESTAR EN CONTACTO CON EL AIRE DICHO METAL SE LLEGA A OXIDAR FORMANDO DOS CLASES DE OXIDO¿CUALES SON ESTOS DOS OXIDOS?
Answer:
Los dos óxidos que forma el cobre son óxido de cobre (I) y óxido de cobre (II) (Cu₂O y CuO, respectivamente).
Explanation:
El cobre posee dos estados de oxidación más comunes, los cuales son +1 y +2.
En contacto con aire el cobre se puede oxidar para dar lugar al óxido cuproso u óxido de cobre (I):
4Cu + O₂ → 2Cu₂O
Dicha oxidación también puede dar lugar a la formación del óxido cúprico u óxido de cobre (II):
2Cu + O₂ → 2CuO
La formación del óxido cúprico se favorece a temperaturas mayores a la del ambiente (por encima de los 300 °C).
Por lo tanto, los dos óxidos que forma el cobre son óxido de cobre (I) y óxido de cobre (II) (Cu₂O y CuO, respectivamente).
Espero que te sea de utlidad!
What kind of reactions are redox reactions
A reaction in which reduction and oxidation take place simultaneously known as a redox reaction.
If you refuse a legal chemical test issued by a law enforcement officer, the Division of Motor Vehicles is required to:
Answer: Revoke the driver's license for at least 12 months
Explanation:
Chemical tests are used in order to measure the amount of drugs or alcohol that is in the body of a person when the person was arrested. To do this, samples of the urine or blood of the person can be taken and the result will be used to know if the person was driving under the influence of alcohol or not.
If the person refuse a legal chemical test issued by a law enforcement officer, the Division of Motor Vehicles is required to revoke the the driver's license of the person for at least 12 months.
