Answer:
There are 27 Valence electrons : )
4+1+1+1+6+4+1+1+4+1+1+1 is 27
Explanation:
There are a total of [5×1]+[2×4]+[7]=21[5×1]+[2 × 4 ] + [ 7]=21 valence electrons
need little help pls
Answer:
0.354 molal
Explanation:
The molarity (M) or the concentration of a solution is defined as the number of moles of a compound in the solution per liter of solution (mol/L), whereas molality, is defined as the number of moles of a compound in the solution per kg of the compound (mol/kg).
Given that the density of the solution is 1.202 g/mL, which is equivalent to 1.202 kg/L. Since the prefix mili- denotes a factor of one thousandth ( [tex]10^{-3}[/tex] ) and kilo- denotes a factor of one thousand ( [tex]{10}^3[/tex] ),
[tex]1.202 \ \frac{g}{mL} \ = \ 1.202 \ \frac{g}{(10^{-3}) L} \ = \ 1.202 \ \frac{{10}^3g}{L} \ = \ 1.202 \ \frac{kg}{L}[/tex].
To calculate the corresponding molality of the solution, the formula
[tex]Molality \ (mol/kg) \ = \ \frac{Molarity \ (mol/L)}{Density \ (kg/L)}[/tex] is used.
Therefore,
[tex]Molality \ = \ \frac{0.426 \ mol/L}{1.202 \ kg/L} \ = \ 0.354 \ mol/kg \ \ (3 \ s.f.)[/tex]
Which element gives up its valence electrons most readily?
Bi
Fr
Be
Ar
Answer:
Fr
Explanation:
I took the test
Find the volume of 8 gram of oxygen gas
please help me and promise I will mark as brainiest I need it in ISEF please
how much energy does the vehicle hydrogen fuel cell need to break hydrogen into ions ?!
Answer: A typical hydrogen fuel cell produces 0.5 V to 0.8 V per cell. To increase the voltage individual cells can be connected in series.
How could you distinguish a compound from a mixture
Answer:
Compound are substances which can be formed by chemically combining two or more elements. Mixtures are substances that are formed by physically mixing two or more substances.A block has 73 kg is being pushed and accelerated at rate of 10 m/s. what force is being applied to the block?
A-730 N
B-7.3 N
C-7300 N
D-730 Kg
Answer:
730 N
Explanation:
force =mass×acceleration
force= 73kg × 10 m/s
f=730N
Calculate the emf of the following concentration cell: Au(s) | Au3+ (0.10 M) || Au3+ (0.50 M) | Au(s)
The emf of the cell as written is calculated to be 0.014 V.
Using the Nernst equation;
Ecell = E°cell - 0.0592/n log Q
We must note that E°cell = 0 because the anode and cathode are composed of the same type of metal.
Now;
Substituting values, we have;
Ecell = 0 - 0.0592/3 log (0.50 M)/(0.10 M)
Ecell = 0.014 V
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Write the symbol for every chemical element that has atomic number less than 13 and atomic mass greater than 17.2 u.
How to find total mass of water in final solution
Answer:
Explanation:
Just like a solid, the density of a liquid equals the mass of the liquid divided by its volume; D = m/v. The density of water is 1 gram per cubic centimeter.
PLEASE HELP WILL GIVE BRAINLIEST
Answer:
55 centimeters
Explanation:
20+15+25
A 4.0 L balloon has a pressure of 406 kPa. When the pressure increases to 2,030 kPa, what is the volume? *
0.4 L
0.8 L
0.2 L
1 L
The new volume when pressure increases to 2,030 kPa is 0.8L
BOYLE'S LAW:
The new volume of a gas can be calculated using Boyle's law equation:
P1V1 = P2V2
Where;
P1 = initial pressure (kPa)P2 = final pressure (kPa)V1 = initial volume (L)V2 = final volume (L)According to this question, a 4.0 L balloon has a pressure of 406 kPa. When the pressure increases to 2,030 kPa, the volume is calculated as:
406 × 4 = 2030 × V2
1624 = 2030V2
V2 = 1624 ÷ 2030
V2 = 0.8L
Therefore, the new volume when pressure increases to 2,030 kPa is 0.8L.
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why is it important to use compound fixative in histology
Answer:
To prevent autolysis (enzymes attack) as well as putrefaction (bacterial attack) of tissues.
Van der Waals bonds initiate
a) Between non-metals
b) Within ionic binds
c) Between metals
d) With H-bond
e) All of the above
I think e no
I am giving you hint
Which muscles is most important to you and why?
Answer:
cardiac muscle
Explanation:
because they help the heart to pump blood to all parts of the body
Answer:
Muscle is also very important to everyone because we need our muscles to survive. The HEART is the strongest muscle in our body and is always looking to get stronger. Muscles enable us to be active and exercise. Our strength comes for our muscles and how much they are used.
Explanation:
#CarryonlearningIf 3.31 moles of argon gas occupies a volume of 100 L what volume does 13.15 moles of argon occupy under the same temperature and pressure
Answer:
397 L
Explanation:
Recall the ideal gas law:
[tex]\displaystyle PV = nRT[/tex]
If temperature and pressure stays constant, we can rearrange all constant variables onto one side of the equation:
[tex]\displaystyle \frac{P}{RT} = \frac{n}{V}[/tex]
The left-hand side is simply some constant. Hence, we can write that:
[tex]\displaystyle \frac{n_1}{V_1} = \frac{n_2}{V_2}[/tex]
Substitute in known values:
[tex]\displaystyle \frac{(3.31 \text{ mol})}{(100 \text{ L})} = \frac{(13.15\text{ mol })}{V_2}[/tex]
Solving for V₂ yields:
[tex]\displaystyle V_2 = \frac{(100 \text{ L})(13.15)}{3.31} = 397 \text{ L}[/tex]
In conclusion, 13.15 moles of argon will occupy 397* L under the same temperature and pressure.
(Assuming 100 L has three significant figures.)
USCTIR ENFIK meaning?
Answer:
la branche de la mécanique concernée par le mouvement des objets sans référence aux forces qui provoquent le mouvement
Answer:
the features or properties of motion in an object.
Check the box under each molecule in the table below that is an isomer of this molecule:
The branched alkanes in boxes two and three all have molecular formula C6H14 and are isomers of the compound shown.
Isomers are compounds that has the same molecular formula but different structural formulas. Hence, isomers of compounds can be represented by the same molecular formula since they contain the same number of each atom.
The molecule shown has molecular formula C6H14. The branched alkanes in boxes two and three all have molecular formula C6H14 and are isomers of the compound shown.
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Look at the diagram of 2 basic cell types. Which of the following describes cell 2?
A) a plant cell
B) an animal cell
C) a eukaryote cell
D) a prokaryote cell
what is oxidation number on Ni in the next compound
K2[NiBr6] ???
Explanation:
The oxidation number of Ni is +4
I’m not sure if it’s the square on the right or left. Please help
Answer:OK im not 100% sure but it should be the right one
Explanation:
What was the name of the original supercontinent that wegener proprosed in his theory
Answer:
pangea
Explanation:
help!!!! the relative formula mass (Mr) of sodium fluoride is 42. Use the correct answer frim the box to complete the sentence.
Answer:
mole
Explanation:
Since Sodium Chloride is ionic, it cannot be considered a molecule as per the definition of a molecule requires each of its components to be bonded together.
The formula mass of a compound is the mass of its one molecule. Since molecule is the basic unit of a compound. Thus, the relative formula mass in grams is the mass of one molecule.
What is sodium fluoride?Sodium fluoride is an ionic compound formed by the combination of sodium and fluorine by loss of one electron from sodium to fluorine. The formula mass of fluorine is calculated from the atomic masses of sodium and fluorine.
Atomic mass of fluorine is 19 g/mol and mass of sodium is 23 g/mol. Here only one sodium and one fluorine is present. Hence the formula mass is 23+ 19 = 42.
This is the mass of one unit of NaF. Thus mass of one sodium fluoride molecule. Where as its molar mass may differ from the formula mass. Since the molar mass is the mass of one mole of the compound NaF. One mole of compound contains 6.02 × 10²³ molecules.
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Tums is a popular remedy for acid indigestion. A typical Tums tablet contains calcium carbonate mixed with inert substances. When ingested, it reacts with stomach acids (hydrochloric acid) to produce carbon dioxide gas. When a 1.241 g tablet reacted with 43.435 mL of hydrochloric acid, carbon dioxide gas was produced and the final solution weighed 52.122 g. Calculate the number of liters of carbon dioxide gas released. When a 1.241g Tums tablet reacted with 43.435 mL of hydrochloric acid (density: 1.140 g/mL), carbon dioxide gas was produced and the resulting solution weighed 50.571 g. Calculate the mass of carbon dioxide gas released.
The mass of CO2 obtained in the reaction by stoichiometry is 30.8 g.
The equation of the reaction is;
2HCl(aq) + CaCO3(s) -----> CaCl2(aq) + H2O(l) + CO2(g)
The mass of the HCl reacted is obtained from;
Density = mass/volume
Mass = Density × volume = 1.140 g/mL × 43.435 mL = 49.5 g
Number of moles of HCl = 49.5 g/36.5 g/mol = 1.4 moles
If 2 moles of HCl reacts produces 1 mole of CO2
1.4 moles of HCl produces x moles of CO2
x = 1.4 moles × 1 mole/ 2 moles = 0.7 moles
Mass of CO2 produced = 0.7 moles x 44 g/mol = 30.8 g
In the second case, the same volume of acid is used hence the same mass of CO2 is obtained.
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what layers of protection can be used tot detect and respond to abnormal reactions or process conditions
In the body, the main protective layer is known as the epithelium, this can be found in the skin as well as other organs such as the lungs.
The body is often exposed to external factors that can damage it; due to this, throughout evolution, most animals and multicellular organisms have developed protective mechanisms.
In the case of humans and other animals, the protective layer is known as the epithelium, which is composed of epithelial cells. This protective layer can be found internally and externally.
External layer: This is the first protective layer, commonly known as skin, this layer protects the inner organs from extreme temperatures, changes in pressure, etc.
Internal layer: Organs such as the lungs or the ones in the gastrointestinal system are all covered by a thin epithelial layer that helps each organ to be protected.
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In what way is the Moon like the Earth?
The Moon has volcanoes.
The Moon has an atmosphere.
The Moon has oceans and seas.
The Moon is a solid, rocky body.
PLS ANSWER RIGHT ILL GIVE BRAINLIST :)
Answer:
The Moon has an atmosphere.
Explanation:
The Moon has an atmosphere, but it is very tenuous. Gases in the lunar atmosphere are easily lost to space. Because of the Moon's low gravity, light atoms such as helium receive enough energy from solar heating so that they escape in just a few hours.
A ramp is at an angle of elevation of 15° . The distance from the top of the ramp to the ground is 20 feet. What is the length of the ramp?
Answer:
Length of ramp = 77.27ft
Explanation:
Step 1 - Sketch a diagram
Make a line about 15 deg. above the horizontal x-axis. Draw the horizontal and vertical components to form a right triangle. See image if you don’t understand.
Step 2 - Label your diagram
Your triangle creates a 15 deg. angle with the x-axis and we know the vertical distance from the top of the ramp to the ground is 20 ft.
Step 3 - Use trig to make an equation and solve
SOH CAH TOA
I’m this problem we know the angle, know “opposite, and we are solving for the hypotenuse of the triangle. Therefore, it would be easiest to use SOH or sin(theta)= (opp./hyp.) Plug in the numbers and solve for the hypotenuse.
All work is shown in the attached image.
The effect of a catalyst is to: change the stoichiometry of the reaction. lower the activation energy of a reaction whereby making it easier for the reactants to get over the energy hump. change the position of the equilibrium. increase the number of collisions between reactants. increase the temperature of the reactants whereby more products are forme
The effect of a catalyst is
Option B(lower the activation energy of a reaction whereby making it easier for the reactants to get over the energy hump)What is a catalystA catalyst allows an alternative reaction pathway that leaves activation energy than the uncatalysed reaction. This does not change the frequency of collision.
Frequency of collisionFrequency of collision depend upon concentration of reactant temperatures
Catalyst on activation energyHence, catalyst lowers the activation energy of reaction thereby making it easier for the reactant to get over the energy hump.
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What other scientific fields are
included in earth science?
Determine the number of moles in 4.9*10 raise to the power of 24 of Ag
Answer:
4.5425806678891E+22mol
Explanation:
What is the lowest frequency photon that can ionize a hydrogen atom with excited state electron configuration 3s^1?