A stent is a small mesh tube that holds open passages in the body, such as weak or narrow arteries.
Explanation:
To open an artery near the heart
just took the quiz
please help me I have to submit
Answer:
A FUSE is a type of conductor which protects the circuit by shorting it down when there is excess flow of current passing through it.
Explanation:
A fuse wire is made up of conducting materials such as alloy of tin and lead that has high resistivity. It has a low melting point of 200°C. It works based on the principle of heating effect of electric current. The functions of fuses include the following:
--> Fuses are made up of thin wire CONDUCTORS which interrupts or breaks the current flow of a circuit when in excess, thereby protecting the circuit from damage.
--> it prevents overload of current. In the event where too many appliances are connected to a single circuit, this can lead to overload which triggers a fuse to terminate the circuit connection.
--> It prevents total black-out: SWITCH-LIKE devices known as CIRCUIT BREAKERS share this function with the fuses. The nearest circuit breaks if any dysfunction occurs in the components of the circuit thereby preventing blackout.
Un compuesto orgánico que contenía solo H y C fue quemado en corriente de O2, encontrándose que 0.210 g daban 0.660 g de CO2.La densidad del vapor del compuesto es de 1.87 g/dm3 a 273 °K y 1 atm. ¿Cuál es la fórmula molecular?
Answer:
[tex]C_3H_6[/tex]
Explanation:
¡Hola!
En este caso, basado en la información dada, es posible calcular las moles de carbono en el compuesto al usar la masa molar del CO2 y la siguiente relación molar:
[tex]n_C=0.660gCO_2*\frac{1molCO_2}{44.01gCO_2}*\frac{1molC}{1molCO_2}=0.015molC[/tex]
Ahora, calculamos las moles de hidrógeno restando la masa de carbono de la de la muestra basado en el siguiente factor molar:
[tex]m_{H}=0.210g-0.015molC*12.01gC/molC=0.030molH[/tex]
Entonces la formula empírica del compuesto resulta:
[tex]CH_2[/tex]
Dado que el carbono y el hidrógeno están en una relación 1:2. Ahora bien, calculamos la masa molar del gas considerando la presión, densidad y temperatura del mismo:
[tex]PV=nRT\\\\PV=\frac{m}{MM}RT \\\\MM=\frac{m}{V}\frac{RT}{P}=\frac{dRT}{P}\\\\MM=\frac{1.87g/dm^3*0.08206\frac{atm*L}{mol*K}*273K}{1atm}=41.9g/mol[/tex]
Es decir que la fórmula molecular y la empírica están en una relación de 3, por lo que la fórmula molecular resulta:
[tex]C_3H_6[/tex]
¡Saludos!
a) explain why caesium is more reactive than potassium.
b) Write the formula of
i) caesium nitrate
ii) caesium sulphate
Answer:
Explanation:
(a) Firstly, caesium abd potassium are both in Group 1 of the periodic table. Group 1 metals (also called alkali metals) are the most reactive metals of the periodic table. Caesium is more reactive than Potassium because it has a higher electropositivity than Potassium. Electropositivity is the tendency of a metal to donate electron(s) to form a cation. Electropositivity increases down the group; this is because it is easier for atoms to loose electrons on the outermost shell that are far away from the central nucleus as against atoms whose outermost electrons are closer to the central nucleus. Thus, the more "bulky" an atom is, the farther it's outermost electrons (valence electrons) get from the central nucleus and the easier it is to lose the outermost electron(s). And the easier it is for the valence electron(s) to be removed, the more reactive the atom would be and vice-versa.
Caesium is more reactive than potassium because it is more bulky than potassium, with an atomic number of 55, while potassium has an atomic number of 19.
NOTE: The closer an electron is to the nucleus, the more difficult it is to be removed from it's shell.
(b) i. Formula for Caesium Nitrate:
Symbol for Caesium is Cs and Nitrate is NO₃⁻.
Cs⁺ + NO₃⁻ ↔ CsNO₃
Formula for Caesium Nitrate is CsNO₃
ii. Formula for Caesium sulphate
Symbol for caesium is Cs and Sulphate is SO₄²⁻
Cs⁺ + SO₄²⁻ ↔ Cs₂SO₄
Formula for Caesium sulphate is Cs₂SO₄
NOTE: When writing the formulae, the charges would be exchanged to form the subscript as seen on the product sides above.
What is the mass of 0.125 moles of tin sulfate (SnSO4)?
Answer:
26.85 grams
Explanation:
The formula for mole calculations is number of moles = given mass/gram-formula mass.
The number of moles is given to us, which is 0.125.
The gram formula mass of SnSO4 is about 214.77.
Plug in the values we have into the equation. It should look like this:
0.125 = x / 214.77
Solve for x by multiplying 214.77 and 0.125. The answer should be about 26.85 grams.
Help please and thank you
Answer:
5. The coefficients are: 2, 7, 2, 4
6. The coefficients are: 1, 4, 1, 2
Explanation:
5. Balancing the equation.
__NO₂ + __H₂ —> __NH₃ + __H₂O
The above equation can be balance as illustrated below:
NO₂ + H₂ —> NH₃ + H₂O
There are 2 atoms of O on the left side and 1 atom on the right side. It can be balance by writing 2 before NO₂ and 4 before H₂O as shown below:
2NO₂ + H₂ —> NH₃ + 4H₂O
There are 2 atoms of N on the left side and 1 atom on the right side. It can be balance by writing 2 before NH₃ as shown below:
2NO₂ + H₂ —> 2NH₃ + 4H₂O
There are 2 atoms of H on the left side and a total of 14 atoms on the right side. It can be balance by writing 7 before H₂ as shown below:
2NO₂ + 7H₂ —> 2NH₃ + 4H₂O
Now the equation is balanced. Thus, the coefficients are: 2, 7, 2, 4
6. Balancing the equation:
__SiO₂ + __HF —> __SiF₄ + __H₂O
The above equation can be balance as illustrated below:
SiO₂ + HF —> SiF₄ + H₂O
There are 4 atoms of F on the right side and 1 atom on the left side. It can be balance by writing 4 before HF as shown below:
SiO₂ + 4HF —> SiF₄ + H₂O
There are 4 atoms of H on the left side and 2 atoms on the right side. It can be balance by writing 2 before H₂O as shown below:
SiO₂ + 4HF —> SiF₄ + 2H₂O
Now the equation is balanced. Thus, the coefficients are: 1, 4, 1, 2
How does light demonstrate quantization?
A. The velocity of a light wave has a direction as well as speed.
B. The wavelength of light increases as the frequency decreases.
C. The frequency of light increases as energy increases.
D. The energy in light waves comes in units called photons.
Answer:
D. The energy in light waves comes in units called photons.
Explanation:
its known as quatum theory
According to Le Châtelier's principle, how will a decrease in concentration of a reactant affect the equilibrium system?
Answer:
a decrease in concentration affects the equilibrium
Explanation:
disturbance: equilibrium was disturbed by a decrease in concentration
response:system acts so as to increase concentration
reaction favoured: forward reaction
concentration: concentration of ...... ND ....... increases ND that of ......(product)decreases
A student accidentally left a bottle of ammonia unclosed in the corner of a laboratory. After a few minutes the entire laboratory smelled of ammonia. Which process has occurred?
Diffusion
Distillation
Evaporation
Brownian motion
Calculate the number of moles of NaOH in an aqueous solution of 36 cm3 of 0.1 mol dm−3.
Answer:
0.0036 moles of NaOH are present
Explanation:
A solution of 0.1mol/dm³ contains 0.1 moles of solute (In this case, NaOH), per 1 dm³ of solution.
36cm³ are in dm³ (1000cm³ / 1dm³):
36cm³ * (1dm³/1000cm³) = 0.036dm³
The moles are:
0.036dm³ * (0.1mol/dm³) = 0.0036 moles of NaOH are present
A slide 3.3 m long makes an angle of 32° with the ground. How high is the top of the slide above the ground?
A. 2.06 m
B. 2.8 m
C. 1.75 m
D. 1.84 m
What is the name of Ba(OH)2
Answer:
Barium Hydroxide
Explanation:
..........................
What effect will this decision have on the American political process? Rucho, et al v. Common Cause
Answer:
If electoral districting is left to incumbent legislatures, it becomes a tool to stack the political process against disempowered opponents
Explanation:
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What is the maximum number of electrons that can occupy a box in an orbital filling diagram at any
energy level?
2
6
8
14
Answer:
2
Explanation:
Which of these compounds would you predict
to have the highest boiling point?
C₂H6
C5H12
C6H14
CH10
C3H8
Answer:c6h14
Explanation:
why doesn't calcium react with water in your body
explain pls
Answer:
Bones aren't made of calcium metal. Bones are a collegun structure filled in with mostly calcium carbonate and some calcium phosphate
Answer:
Bones aren't made of calcium metal. Bones are a collegun structure filled in with mostly calcium carbonate and some calcium phosphate
Explanation:
I hope this helps
what are the compounds for the chemical formula B4S
Answer:
boron sulfide
b=boron
s=sulfer
Explanation:
which element is most reactive among aluminium, boron, calcium and beryllium? Give reason.
Answer:
Well, if you check the reactivity series, calcium is more reactive than magnesium. This means there's a a trend of increasing reactivity as we go down the group. As beryllium is above magnesium, it must be the least reactive. Then magnesium is in the middle and the most reactive has to be calcium.
Answer:
Aluminium because highl elecronegativety element and more metalic hign melting and boling point from the other
When copper is heated in air, the solid product that is formed has a greater mass than the original copper. When calcium carbonate is heated in air, the solid product that is formed has less mass than the original
calcium carbonate. Why is the mass of the solid product greater in one reaction but less in the other reaction?
Answer:
When heated, oxygen reacts with copper to form copper oxide. If this reaction occurs in a sealed container, will the mass of the container and everything in it increase, decrease, or stay the same and why? The mass will increase because a new kind of molecule is formed.
Explanation:
As above, carbonates decompose upon heating to give the metal oxide and carbon dioxide. The mass is lost as carbon dioxide.
To solve this we must be knowing each and every concept related to mass. Therefore, Carbon dioxide is released as the mass is depleted when carbonates are heated.
What is mass?Mass defines the quantity of a substance. It is measured in gram or kilogram. Average mass is the mass of atoms of an element that are isotopes.
When copper was heated in the air, the resulting solid product has a larger mass than the initial copper. When calcium carbonate was heated in air, the resulting solid product has much less mass than the initial calcium carbonate. When carbonates are heated, they breakdown into metal oxides and carbon dioxide. Carbon dioxide is released as the mass is depleted.
Therefore, Carbon dioxide is released as the mass is depleted.
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What is the value of the quantum number n for a spin-up electron in a 2p orbital?
A. +2
B. -1/2
C. +1
D. +1/2
Answer:
+1/2
Explanation:
spin up is always +1/2
PLEASE HELP THIS IS AN EMERGENCY!!!!!
An atom's electron configuration ends with 3p3. If another atom has nine more electrons, what would be the continuation of the electron configuration? (5 points)
A.)3p64s23d4
B.)03p34s23d7
C.)3p63d44s2
D.)3p33d74s2
Answer:
A.) is the correct answer
The continuation of the electronic configuration would be 3p6, 4s2, 3d4
The initial p-orbital (the 3p3) is incompletely filled. Thus, the first thing would be to fill it completely (3p6) so as to obey the orbital-filling rule. This leaves 6 more electrons
After 3p orbital, the next orbitals are 4s, 3d, 4p, 5s, etc.
The 4s orbital will take a maximum of 2 electrons, leaving 4 more electrons.
Next would be the 3d orbital which can take a maximum of 8 electrons, but only 4 electrons are left.
Thus, the electronic configuration would be 3p6, 4s2, 3d4.
More on electron configuration can be found here: https://brainly.com/question/18914648?referrer=searchResults
If you increase the amount of Reactant A, the reaction rate will also increase.
What is this statement an example of?
A. A theory
B. An observation
C. A hypothesis
D. A scientific question
sulphur dioxide reacts with oxygen to produce sulphur trioxide, balance the chemical equation using lcm method?
Answer:
2SO2 + O2 → 2SO3
Explanation:
According to this question, sulphur dioxide (SO2) reacts with oxygen to produce sulphur trioxide (SO3). The equation is as follows:
SO2 + O2 → SO3
The above equation is unbalanced because there are unequal number of atoms of each element in the both reactants and products. To balance the equation, we use coefficients to make the number of atoms equal. The balanced equation is as follows:
2SO2 + O2 → 2SO3
- There are 2 moles of S on both sides of the equation.
- There are 4 moles of Oxygen on both sides of the equation.
The diagram shows the breathing system in a human. What does label 1 show?
Answer:
parietal pleura
Explanation:
The pleurae, which are serous membranes, divide the thoracic cavity's wall from the lungs. The parietal pleura covers the interior of the thorax, mediastinum, and diaphragm, while the visceral pleura covers the surface of the lungs.
What is the function of parietal pleura?The perianal pleura, the outer layer, is attached to the chest wall. The lungs, mediastinum's neurovascular structures, and bronchi are all covered by the inner layer (visceral pleura).
The pleura's role in breathing is to enable the lungs to expand and collapse as efficiently as possible.
The parietal and visceral pleura can move over one another without rubbing against one another thanks to the pleural fluid's lubricating properties. The pleural layers themselves produce this fluid.
Therefore, parietal pleura, which surround the lungs in thoracic cavity.
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8. (05.03 MC) How does temperature influence the appearance of a star? Give an example in your response. (4 points)
Answer:
Stars have the different colors that make up white light, the color of a star is related to the wavelength of the light which is emitted by the star which is related to the temperature of the star's surface
Very hot temperatures yield hotter wavelength, which light having short wavelength being bluish, the blue and blue-white stars are the hottest stars, while stars which emit longer wavelength and therefore have a color of brown and red have a cooler surface temperature
The surface temperature of a star also has an effect on the bright appearance of a star. The higher the temperature of a star the higher the heat energy given off and the brighter the star will be, as a star that gives off more energy is brighter than one that gives less energy
Explanation:
Our solar system is more than _________ in diameter.
Answer: 287.46 billion km
Explanation: calculated it myself. nah but thats the answer
What is the pH of a solution with a concentration of 4.2 x 10−5 M H3O+? (4 points)
Select one:
a. 2.31
b. 4.38
c. 5.62
d. 6.87
What is the pH of a solution with a 4.60 x 10−4 M hydroxide ion concentration? (4 points)
Select one:
a. 0.663
b. 3.33
c. 10.1
d. 10.7
Answer:
1) b. 4.38
2) d. 10.7
Explanation:
1) The problem tells us that [H₃O⁺] = 4.2x10⁻⁵ M, and keeping in mind that [H₃O⁺]= [H⁺], we can calculate the pH of the solution:
pH = -log[H⁺] = 4.382) First we calculate the pOH of the solution:
pOH = -log[OH⁻] = -log(4.6x10⁻⁴) = 3.33Then we calculate the pH using the following formula:
pH = 14 - pOH = 14 - 3.33pH = 10.7The pH of a solution with a concentration of 4.2x10⁻⁵ M H₃O⁺ ion is 4.38 and of a solution with a concentration of 4.6x10⁻⁴ OH⁻ ion is 10.7.
What is pH and pOH?pH of any solution is define as the negative log of the concentration of H⁺ ions and pOH is define as the negative log of the concentration of OH⁻ ions.
Given that concentration of H⁺ ions in solution = 4.2x10⁻⁵ M
pH for this solution is calculated as:
pH = -log(4.2x10⁻⁵) = 4.38
Also given that concentration of OH⁻ ions in solution = 4.6x10⁻⁴
pOH = -log(4.6x10⁻⁴) = 3.33
We know that, pH + pOH = 14.
pH = 14 - 3.33 = 10.7
Hence, value of pH & pOH is 4.38 and 10.7 respectively.
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Explain how you determine the molar mass of Al2(SO4)3
Molar Mass of Al = 27
Molar Mass of S = 32
Molar Mass of O = 16
Putting the molar mass value in Al2 (SO4) 3
27 x 2 + 3 ( 32 + 16 x 4)
54 + 3 ( 32+ 64)
54 + 3 x 96
54 + 288
342
A bird has flown 300 metres for 6 hours. What is the bird's speed? Formula for speed = d/t * 2 points
40 m/hr
50 m/s
50 m/h
50 m/min
Answer:
C
Explanation:
d=300
t=6hr
speed=?
speed=300/6
speed=50m/hr the important thing in this question is to get the right units
Which fundamental force(s) can act over very long distances?
A. Gravity and electrostatic force
B. Strong nuclear force and weak nuclear force
C. Gravity only
D. Electrostatic force and strong nuclear force
Answer:
C. Gravity only
Explanation:
TIMED PLS HELP ASAP AND WILL GIVE BRAINLIST
Given the following reaction:
2 Al + 2 KOH + 4 H2SO4 + 22 H2O --> 3 H2 + 2KAl(SO4)2•12H2O
If you start with 8.3 mL of 9.9M sulfuric acid, what is the theoretical yield of alum?
Answer: The theoretical yield of alum is 12.09 g
Explanation:
Molarity is calculated by using the equation:
[tex]\text{Molarity}=\frac{\text{Moles}}{\text{Volume}}[/tex] ......(1)
We are given:
Molarity of sulfuric acid = 9.9 M
Volume of solution = 8.3 mL = 0.0083 L (Conversion factor: 1 L = 1000 mL)
Putting values in equation 1, we get:
[tex]\text{Moles of sulfuric acid}=(9.9mol/L\times 0.0083L)=0.08217mol[/tex]
The given chemical equation follows:
[tex]2Al+2KOH+4H_2SO_4+22H_2O\rightarrow 3H_2+2KAl(SO_4)_2.12H_2O[/tex]
By the stoichiometry of the reaction:
4 moles of sulfuric acid produces 2 moles of alum
So, 0.08217 moles of sulfuric acid will produce = [tex]\frac{2}{4}\times 0.08217=0.0411mol[/tex] of alum
The number of moles is defined as the ratio of the mass of a substance to its molar mass. The equation used is:
[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}[/tex] ......(2)
Molar mass of alum = 294.24 g/mol
Plugging values in equation 2:
[tex]\text{Mass of alum}=(0.0411mol\times 294.24g/mol)=12.09g[/tex]
Hence, the theoretical yield of alum is 12.09 g