why is it dangerous to wear contact lenses in the lab
Answer:
It is strongly recommended that students do NOT wear contacts lenses in the laboratory. Chemical vapors may penetrate the contact lens material and cause the lens to adhere to one's eye, which could be detrimental to the eye. Goggles are not vapor tight and do not completely eliminate this absorption.
what is the mechanical hound in the book fahrenheit 451
Explanation:
The Mechanical Hound is a robotic animal that firemen can deploy to hunt and catch fugitives. It can be trained and programmed to hunt its prey very quickly by smell. Once it catches its prey, the Hound injects the person with a sedative; unable to run, the drugged fugitive is easily captured.
PLS HELP
Answer this question and I will mark you the braninliest! <3
Answer:
the left one
Explanation:
heavier means it goes faster
mass of 0.5 moles of co2
Answer:
Mass of 0.5 moles of CO2 is 22 gm.
Explanation:
1 mole of CO2 = 44 gm
0.5 mole of CO2 = 0.5 × 44 = 22 gm
how many pounds of gold are present in 1 cubic mile of seawater?
Answer:
38 pounds of gold in cubic mile of seawater.
15 points who can solve help plsss now
Answer:
C. Al and O2
Explanation:
The reactants are the elements or compounds that is becoming the result
So Al and O2
Hope this helps!
Please help !!!!!!!!
1) Write the equation for the reaction between the hydrocarbon and bromine using fully displayed formulae for the hydrocarbon and the organic product.
2) The reaction between methane and bromine gas in the presence of UV light also causes the bromine to lose color.
(a) Write an equation for this reaction
(b) This reaction is described as a substitution reaction. whereas the reaction between X and bromine is an addition reaction. Using the equations you have already written , explain the difference between addition and substitution
True or false? In giant covalent structures the atoms form strong bonds by sharing electrons.
Answer:
True
Explanation:
its true don't lie on here please
In giant covalent structures such as graphite or diamond, the atoms form strong bonds by sharing electrons. Therefore, the given statement is true.
What is a covalent bond?A covalent bond can be defined as a chemical connection formed by the sharing of electron sets between particles. A covalent bond can be created by the mutual sharing of electrons from both atoms.
The pair of electrons that are shared in this kind of bonding is known as the shared or bonding pair. Covalent bonds are the sharing of bonding pairs of electrons that will provide the stability of the atom in its outer shell.
Elements that have very high ionization energies are incapable of exchanging electrons or elements having low electron affinity cannot accept electrons. Covalent bonding between two non-metallic atoms is characterized by the equal sharing of electrons between the atoms and covalent bonds with an electronegativity difference of participating atoms is more than 2.0.
Therefore, a giant structure like a diamond has strong covalent bonds that require a lot of energy to break.
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the product of 13cm and 5.7cm is correctly reported as
a. 75cm^2
b. 74.0cm^2
c. 74 cm^2
d. 74.1 cm^2
Answer:
d] 74.1 cm²
Explanation:
Product means that the values given must be multiplied.
13 cm × 5.7 cm = 74.1 cm²
Iridium crystallizes in a face-centered cubic unit cell that has an edge length of 3.833 Å.
(a) Calculate the atomic radius of an iridium atom.
(b) Calculate the density of iridium metal
a.
The atomic radius of iridium is 1.355 Å
For a face-centered cubic unit cell, with edge length, a and atomic radius r,
we have a² + a² = (4r)²
2a² = 16r²
r² = a²/8
r = a/√8
Since a = 3.833 Å,
Substituting this into the equation, we have
r = a/√8
r = 3.833 Å/√8
r = 3.833 Å/2.828
r = 1.355 Å
So, the atomic radius of iridium is 1.355 Å
b.
The density of iridium metal is 22.67 g/cm³
To find the density of the iridium metal, we need to find the mass of atoms per unit cell.
So, for the face centered cubic iridium atom, there are 6 faces per unit cell × 1/2 atoms per face + 4 corners per unit cell × 1/4 atoms per corner = 3 atoms + 1 atom = 4 atoms per unit cell.
So, the mass of the atoms in the unit cell is m = number of atoms/cell × number of moles/atom × molar mass of Iridium
= 4 atoms/cell × 1 mol/6.022 × 10²³ atoms × 192.22 g/mol
= 768.88/6.022 × 10²³ g/cell
= 127.68 × 10⁻²³ g/cell
= 1.2768 × 10⁻²¹ g/cell
Next, we need to find the volume of the unit cell which is V = a³
= (3.833 Å)³
= (3.833 × 10⁻¹⁰ m)³
= 56.314 × 10⁻³⁰ m
= 5.6314 × 10⁻²⁹ m
So, the density of iridium = mass of unit cell/volume of unit cell
= m/V
= 1.2768 × 10⁻²¹ g/cell ÷ 5.6314 × 10⁻²⁹ m
= 0.2267 × 10⁸ g/m³
= 0.2267 × 10⁸ g/m³ × 10⁻⁶ m³/cm³
= 0.2267 × 10² g/cm³
= 22.67 g/cm³
So, the density of iridium metal is 22.67 g/cm³
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hydrogen ions ________ acidity of the water which is a key point.
Answer:
Raise
Explanation:
H+ ions are acidic and lower the PH of water.
a scientist finds an organism that has a single cell without a nucleus.This organism was found in pond water.In which KINGDOM douse it belong?if you can explain
Archaea (Archaeon ): Single-celled microorganisms without nuclei and with membranes different from all other organisms. Once thought to be bacteria.
Unicellular organism
-A unicellular organism, also known as a single-celled organism, is an organism that consists of a single cell, unlike a multicellular organism that consists of multiple cells. Unicellular organisms fall into two general categories: prokaryotic organisms and eukaryotic organisms.
CH4+4S-CS2+2H2S
how many moles of CS2 can be formed by the complete reaction of 10.6 mol of S
Let's check the equation
[tex]\\ \sf\longmapsto {CH_4\atop 1mol}+{4S\atop 4moles}\longrightarrow {CS_2\atop 1mol}+{2H_2S\atop 2moles}[/tex]
4moles of S gives 1 mol of CS21mol of S gives 1/4=0.25mol of CS210.6mol of S gives:-[tex]\\ \sf\longmapsto 10.6(0.25)=2.65moles\:of\:CS_2[/tex]
preventive maintenance on a hot water heater includes:
A water heater can be regularly maintained by flushing it at least two times in a year.
A water heater is a device that is used to heat up water for home use. There are different types of water heaters but they all serve the same purpose at home. In order to maintain maximum efficiency, the water heater must be maintained regularly.
The following are routine maintenance operations on a water heater;
Inspect the heater regularly to ascertain if there are faults.Flush the heater at least two times each year.The anode rod should be changed after a couple of yearsLearn more about water heater;https://brainly.com/question/4751630
What does it mean by solution in salt solution, sugar solution, etc.
which term best describes a unit of carbon dioxide?
Answer:
Molecule.
Explanation:
carbon and fluorine. Based on the bonding, a unit of carbon dioxideis described as a molecule.
Which substances will make a salt when combined?
Vinegar and tea
Soda and wine
Soda and ammonia
Fertilizer and detergent
Answer:
Soda and wine is the answer to your question.
Explanation:
yo make salt you need a base and an acid. in this case the base is soda and the wine is acid. hope that helps :)
A scientist tested a series of solutions to determine their pH, and recorded the results in this table.
Substance pH
A 9
B 12
C 11
D 14
According to this data, which solution would be most effective at neutralizing a strong acid?
Substance A
Substance B
Substance C
Substance D
Answer:d
Explanation:
Each cart below is pushed across a room with the same amount of force. Which cart will result in the greatest change in speed?
F.A 75 kg cart being pushed with a 200 N force
G.A 125 kg box being pushed with a 200 N force
H.A 350 kg box being pushed with a 200 N force
J.A 450 kg cart being pushed with a 200 N force
The cart with the greatest change in speed is the cart with a mass of 75 Kg
Acceleration is defined as the change in velocity of an object with time. Also, acceleration is related to the force and mass according to the following equation:
Acceleration (a) = Force (F) / mass (m)
a = F / mTo answer the question, we shall determine the acceleration of each cart.
For cart of mass 75 kgMass (m) = 75 KgForce (F) = 200 NAcceleration (a) =?a = F / m
a = 200 / 75
a = 2.67 m/s²For cart of mass 125 kgMass (m) = 125 KgForce (F) = 200 NAcceleration (a) =?a = F / m
a = 200 / 125
a = 1.6 m/s²For cart of mass 350 kgMass (m) = 350 KgForce (F) = 200 NAcceleration (a) =?a = F / m
a = 200 / 350
a = 0.57 m/s²For cart of mass 450 kgMass (m) = 450 KgForce (F) = 200 NAcceleration (a) =?a = F / m
a = 200 / 450
a = 0.44 m/s²From the above illustrations, we can see that the cart with a mass of 75 K has the greatest change in speed (i.e 2.67 m/s²)
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Answer:
D
Explanation:
F. 200-75=125
G. 20-125=75
H. 350-200=150
J. 450-200=250
250 is the biggest number so it has the biggest change
A sample of Ammonia gas at 650mmHg and 15 degree has a mass of 56.8g.calculate the volume occupied by the gas. Take N=14, H=1,R=8.3145jk.
Answer:
The first thing we have to do is change and state all the units so that we can use our ideal gas law equation ([tex]PV = nRT[/tex]).
650 mmHg is a pressure unit, we have to convert this to kiloPascals. We know that 760 mmHg gives us 101 kPa.
[tex]650 \ mmHg \ * \ \frac{101kPa}{760 mmHg} = 86 \ kPa[/tex]
P = 86kPa
T = 15°C + 273K = 288K
R (Gas constant) = 8.31 kj/mol
Molar mass of Ammonia ([tex]NH_{3}[/tex]) = (1 x 3) + (14) = 17g/mol
n (moles) = [tex]\frac{mass}{molar \ mass}[/tex] [tex]= \frac{56.8}{17} =[/tex] 3.34 mol
V = ?
Rearrange the equation to solve for Volume:
[tex]V = \frac{nRT}{P}[/tex]
Substitute the values inside:
V = [tex]\frac{(3.34)(8.31)(288)}{(86)} = 93 L (rounded)[/tex]
Therefore 93 L of volume is occupied by the ammonia gas.
What are 2 substances that will NOT conduct electricity? Plz explain.
Answer:
Covalent compounds (solid liquid solutions)
non-metal elements are insulators but not conductors of electricity.
Explanation:
Metal elements and carbon (graphite) are conductors of electricity
PLEASE HELP!!
Explain the physical and chemical properties of water, including its different phase changes. Why is water so critical for human life?
Submission
plizzz helpppp
consider the photo
What is an allotrope?
a) The same atom with a different number of neutrons
b) A radioactive substance
c) An alternative form of an element
d) Diamond
Which statement concerning simple sugars and amino acids is correct
Answer:
Is there be suppose a file with this?
Explanation:
which best explains why water dissolves most salts?
Answer:
where are the answers?
Explanation:
How many moles of CO2 are produced from 15.6 g of NaHCO3?
Answer:
0.185moles
Explanation:
1mole of bicarbonate produces 1mole of CO2
so 0.185 mole produces 0.185 moles of CO2
4. If 100.0 g of water is cooled from 25.3°C to 16.9°C, what quantity of
energy has been transferred from the water?
Answer:
Dived the numbers by each other
Explanation:
25.3/19.9
what is the empirical formula of cinnamaldehyde?
C9H8O. .....................
Sulfur reacts with oxygen to form sulfur dioxide (SO2(g), Delta. Hf = â€"296. 8 kJ/mol) according to the equation below. Upper S (s) plus upper O subscript 2 (g) right arrow upper S upper o subscript 2 (g). What is the enthalpy change for the reaction? Use Delta H r x n equals the sum of delta H f of all the products minus the sum of delta H f of all the reactants. â€"593. 6 kJ â€"296. 8 kJ 296. 8 kJ 593. 6 kJ.
The enthalpy of this reaction is -296. 8 kJ/mol.
The equation of the reaction is;
S(s) + O2(g) -----> SO2(g)
Recall that the enthalpy of the reaction can be obtained from the formula;
ΔHrxn = ΔHf(products) - ΔHf(reactants)
We know that;
ΔHf S(s) = 0 KJ/mol
ΔHf O2(g) = 0 KJ/mol
ΔHf SO2(g) = -296. 8 kJ/mol
Hence;
ΔHrxn = -296. 8 kJ/mol - [0 KJ/mol + 0 KJ/mol]
ΔHrxn = -296. 8 kJ/mol
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