Answer:
22.4 L
Explanation:
Write a chemical equation of Dr. Jeff's demonstration using a battery to light steel wool on fire. The battery is used to allow a current to travel through the steel wool, thus heating it. Steel wood is made from iron (Fe).
Answer:
2Fe(s) + 3O2(g) --------> 2FeO3(s)
Explanation:
According to the question, a battery was used to light the steel wool by bringing the terminals very close together. When the battery came into contact with the steel wool, current was sent out through the thin wire. This caused the iron to heat up quite well.
Iron reacts with oxygen under these conditions as follows;
2Fe(s) + 3O2(g) --------> 2FeO3(s)
This is the chemical reaction that occurs when the steel wool is set on fire.
Chemical equation involved in Dr. Jeff's demonstration is
2 Fe+3 O₂[tex]\rightarrow[/tex]2 FeO₃
What is the effect of heating in chemical reactions?Battery is a device which helps in conduction of current. When a battery is used to pass a current through a substance in this case which is steel wool made up of iron it starts getting heated up.
The amount by which substance gets heated up is directly proportional to the current passing through it. As more current is passed through the battery it gets heated more.
During heating, the iron present in the steel wool reacts with oxygen to form iron oxide with iron present in the+3 oxidation state.When the heat exceeds a certain point the steel wool catches fire due to the heat generated. The heat causes the electrons present in steel wool of iron to move faster and collide with each other thus generating more heat.
Learn more about effect of heat in chemical reactions:
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if the bending of rocks is to much what would happen? a. the rock will break
b. the rock will continue to fold
c. the rocks will be flattened
d. the rocks will build up an energy
Answer:
a, u cannot bend rocks
Explanation:
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What is it that lives if it is fed, and dies if you give it a drink
Answer:
fire
Explanation:
Answer:
ants if you splash a ant with sum water that shít is dead
What coefficient will balance the equation that is shown?
Al +_ HCI-H2 + ALCI,
Balanced equation :
2Al +6HCI⇒ 3H₂ + 2AlCI₃
Further explanationGiven
Reaction (unbalanced)
Al +HCI⇒ H₂ + ALCI₃
Required
Balanced equation
Solution
Give a coefficient
aAl +bHCI⇒ cH₂ + AlCI₃
Al, left = a, right=1⇒a= 1
Cl, left = b, right=3⇒b=3
H, left = b, right=2c⇒b=2c⇒3=2c⇒c=3/2
The equation becomes :
Al +3HCI⇒ 3/2H₂ + AlCI₃ x 2
2Al +6HCI⇒ 3H₂ + 2AlCI₃
Can someone answer ASAP if you hurry I will mark brainliest
Answer:
Electrical and magnetic
You exert a gravitational force on the pupil and the pupil exerts an equal gravitational force on you. ... The size of the gravitational force depends on the mass of the objects involved. The greater the mass, the greater the gravitational force.
Explanation:
Types of osmosis...in 50 words
Osmosis is of two types:
Endosmosis– When a substance is placed in a hypotonic solution, the solvent molecules move inside the cell and the cell becomes turgid or undergoes deplasmolysis. This is known as endosmosis.
Exosmosis– When a substance is placed in a hypertonic solution, the solvent molecules move outside the cell and the cell becomes flaccid or undergoes plasmolysis. This is known as exosmosis.
There are some variations or types of osmosis on the basis of the direction of the movement of solvent molecules.
Reverse osmosis is a method of separation that is used to force a solvent through a semi-permeable membrane resulting in solute molecules on one side and solvent molecules on the other side.Reverse osmosis is different than the forward osmosis in that reverse osmosis utilized hydraulic pressure to force the solvent against the osmotic pressure.Forward osmosis is another variation of osmosis where the osmotic pressure gradient is used to induce the flow of water from the sample solution to separate the solutes.Forward osmosis uses a draw solution with a higher concentration of solute, which extracts the solvent molecules from the sample solution; thus, resulting in the separation of solute and solvent in the sample solution.Endosmosis is the movement of water into the cell which occurs when a cell is placed in a solution having a higher concentration of water than the cell.Exosmosis is the movement of water out of the cell which occurs when a cell is placed in a solution having a higher concentration of solute than the cell.If half of a radioactive isotope decays in one hour, how much of the original isotope will remain after three hours?
Answer:
1/8
Explanation:
Use logic,
every one hour, half of a radioactive remains
for the first hour, half remains
for the second hour, half of half remains or quarter remains
for the third hour, 1/2 of 1/2 of 1/2 or 1/8 remains
or use this equation
[tex]n = r ({ \frac{1}{2} })^{ \frac{f}{t} } [/tex]
where
n = amount after f time
r = amount of the original isotope
f = time
t = half-life
PLEASE HELP ADAP I WILL MARK AS BRAINLYEST
Answer:
c! Hope this helps!
Explanation:
BRAINLIEST PLZ ;)
Answer:
I think its the third one im not sure tho
Explanation:
What is the Law of Conservation of matter, and how does it apply to chemical reactions?
Answer: This law states that, despite chemical reactions or physical transformations, mass is conserved — that is, it cannot be created or destroyed — within an isolated system. In other words, in a chemical reaction, the mass of the products will always be equal to the mass of the reactants.
What does a triangle written above the arrow in an equation
represent?
Answer:
If the reaction requires energy, it is often indicated above the arrow. A capital Greek letter delta (Δ) is written on top of the reaction arrow to show that energy in the form of heat is added to the reaction; hv is written if the energy is added in the form of light.
Answer:
it means that to get the product, the reactants were heated
A dolphin travels a distance 20 miles up the coastline in 153 minutes.If 1 mile is equal to 1609 meters,then what is the dolphins average speed in meters/seconds rounded to the nearest tenth?
Answer:
The dolphins average speed is 3.51 [tex]\frac{meters}{seconds}[/tex]
Explanation:
First of all, the following rules of three should be applied:
If 1 mile is equal to 1609 meters, 20 miles are equal to how many meters?[tex]distance=\frac{20 miles*1609 meters}{1 mile}[/tex]
distance=32,180 meters
If 1 minute is equal to 60 seconds, 153 minutes is equal to how many seconds?[tex]time=\frac{153 minutes*60 seconds}{1 minute}[/tex]
time= 9,180 seconds
Speed is a physical quantity that expresses the relationship between the space traveled by an object and the time used for it. That is, speed implies the change of position of an object in space within a certain amount of time and is calculated as:
[tex]speed=\frac{distance}{time}[/tex]
So in this case the velocity is calculated as:
[tex]speed=\frac{32,180 meters}{9,180 seconds}[/tex]
Solving, you get:
Speed= 3.51 [tex]\frac{meters}{seconds}[/tex]
The dolphins average speed is 3.51 [tex]\frac{meters}{seconds}[/tex]
What is the coefficient for this formula? 9 NaCl2 A. 11 B. 9 C. 2 D. 1
Answer:
B. 9
Explanation:
The formula of the compound is given as:
9NaCl
Coefficient is the number before the compound. The compound here is made up of sodium and chlorine.
Therefore, we have 9 as the coefficient and it is 9 moles of NaCl.
The compound have 1 atoms of NaAlso 1 atom of ClNote, NaCl is an ionic compound.
What is the best way to make a supersaturated solution?
A. Heat the solution
B. Cool the solution
C. Stir the solution
D. Evaporate the solution
Answer:
A
Explanation:
how many moles of oxygen atoms are in one mole of the molecule Ca5(PO4)3OH? could you also show work
Answer:
13 moles of oxygen
Explanation:
A mole of a substance is the unit of measuring the number of particles within a chemical substance.
The given compound is:
Ca₅ (PO₄)₃OH
This is a mole of Ca₅ (PO₄)₃OH
In this compound we have:
5 moles of Ca
3 mole of P
13 mole of O
1 mole of H
So,
In 1 mole of Ca₅ (PO₄)₃OH, we have 13 moles of oxygen
Lava that cools quickly forms: A. basalt B. granite C.quartz D. none the above
Answer:
I think the answer would be B. hope this helps!!
Explanation:
A piece of mental with a mass of 106 g is placed in a 50 mL graduated cylinder.The volume rises from 20 mL to 31 mL. What is the destiny of the metal?
Answer:
9.64g/mL
Explanation:
Given parameters:
Mass of the metal = 106g
Volume of cylinder = 50mL
Volume difference = 31mL - 20mL = 11mL
Unknown:
Density of the metal = ?
Solution:
To find the density of the metal, we use;
Density = [tex]\frac{mass}{volume}[/tex]
Density = [tex]\frac{106}{11}[/tex] = 9.64g/mL
What is an empirical formula
An empirical shows the simplest ratio among atoms in a compound .
More informationan empirical formula is the simplest formula for a compound .For example, H2O2 can be reduced to a simpler formula. Determining a Molecular Formula from an Empirical Formula The empirical formula for a compound is P 2 O 5 . Its experimental molar mass is 284 g/mol.For example, the empirical formula of benzene (C5H5) is Qj, - because the mole ratio of carbon am'hydrogen is 1:1.Help!
(Chose all the right answers)
Glucose is made of molecules with the chemical formula seen in the picture
What can we say about glucose molecules?
A) There are 3 different types of atoms in glucose
B) 2 glucose molecules would have 12 C atoms in total
C) Glucose is an element
D) Each glucose has 18 atoms in total
SOMEONE HELP PLS ILL GIVE BRAINLIEST AND 19 PT
Sample left = 6.25 g
The percentage = 6.25%
Further explanationGiven
t1/2 = half-life = 3.8 days
t = decay time = 15.2 days
No = initial sample = 100 g
Required
Nt = final sample left
The percentage
Solution
General formulas used in decay:
[tex]\large{\boxed{\bold{N_t=N_0(\dfrac{1}{2})^{t/t\frac{1}{2} }}}[/tex]
Input the value :
[tex]\tt N_t=100.\dfrac{1}{2}^{15.2/3.8}\\\\N_t=100.\dfrac{1}{2}^4\\\\N_t=6.25~g[/tex]
The percentage : Nt/No
6.25 : 100 = 6.25%
4. Which of the following have mass? Select all that apply.
O A neon-filled tube.
A diamond.
Water in a glass
The helium in a balloon.
Answer:
All except a diamond
Explanation:
The helium in the balloon has mass it fills the space its in.
The neon-filled tube has mass because it takes up space.
Water in a glass has mass because the water is taking up space.
A diamond does not because it does not take up space.
Which of the following is an example of an electromagnetic wave?
Seismic wave
Radio wave
Water wave
Sound wave?
Answer:
Radio wave
Explanation:
Radio waves are a type of electromagnetic wave radiation with wavelengths in the electromagnetic spectrum longer than infrared light
A seismic wave is an elastic wave generated by an impulse such as an earthquake or an explosion.
Sound and water waves are mechanical waves; meaning, they require a medium to travel through.
How many different methods can you list for how we generate electricity in this country. Which of those methods do we use the most, and which of them should we invest more in
Answer:
1. Broadly, there are three different methods for how electricity is generated in the United States. They include; Fossil fuels, Nuclear energy, and Renewable energy sources.
2. Fossil fuels, are used the most, with Natural gas topping the list by 38%.
3. More should be invested into renewable gas. It is a clean source of energy and investing in it would bring about a cleaner and safer environment.
Explanation:
Fossil fuels arise from plants and animals that have been long dead and can can now be converted to sources of energy. Examples include; coal natural gas, crude oil. etc.
Nuclear energy arises from the fission of uranium atoms, nuclear decay, and nuclear fusion. They are safe since green house gases are not emitted. Thermal energy can be generated as the byproduct of these reactions.
Renewable sources of energy are generated from natural sources which are always available. Examples are; sun, wind, biomass, water, and geothermal sources,
What mass in grams would 5.7L of hydrogen gas occupy at STP?
Answer: The correct answer is: " 0.54 g " .
__________________________________________
Explanation:
Note that "hydrogen gas" is:
H₂ (g) ; that is: a "diatomic element" (diatomic gas) ;
_________________________________________
The molecular weight of "H" is: 1.00794 g ;
(From the Periodic Table of Elements).
So, the molecular weight of: H₂ (g) is:
" 1.00794 g * 2 = 2.01588 g ; {use calculator) ;
_________________________________________
Note the conversion for a gas at STP:
______
1 mol of a gas = 22.4 L gas;
___
i.e. " 1 mol / 22.4 L " ;
____
So: " 5.7 L H₂ (g) [tex]* \frac{1 mol H_{2} }{22.4 L} *\frac{2.01588 g}{mol} =? ;[/tex]
The "L" ("literes" cancel out to "1" ; since "L/L = 1 ;
The "mol" (moles) cancel out to "1" ; since "mol/mol = 1 ;
____
and we are left with:
____
[5.7 * 2.104588 g ] / 22.4 = ? g ;
______________________
→ [ 11.9961516 g ] / 22.4 =
0.53554248214 g ;l
_____________________________
We round this value to: " 0.54 g " ;
→ since "5.7 L " has 2 (two) significant figures;
22.4 is an exact number conversion;
and "5.7 L" has fewer significant figures than:
" 2.104588 " ; or: " 1.00794 " .
→ as such: We round to "2 (two) significant figures."
______________________________
Hope this is helpful. Wishing you the best in your academic endeavors!
_______________________________
Bertie instructs his butler, Jeeves, to make him 40g of calcium oxide (CaO). How much CaCO3 does Jeeves need to find?
Answer:
The amount of CaCO₃ Jeeves needs to find is approximately 71.392 grams
Explanation:
The given parameters are;
The mass of the CaO required = 40 g
The chemical reaction for the production of CaO from CaCO₃ is given as follows;
CaCO₃(s) → CaO(s) + CO₂(g)
Therefore, 1 mole of CaCO₃ produces 1 mole of CaO and 1 mole of CO₂,
The molar mass of CaO = 56.0774 g/mol
Number of moles, n = Mass/(Molar mass)
The number of moles of CaO = 40 g/(56.0774 g/mol) ≈ 0.7133 moles of CaO
Therefore, given that 1 mole of CaO is produced from 1 mole of CaCO₃ 0.7133 moles of CaO will be produced from 0.7133 moles of CaCO₃
The molar mass of CaCO₃ = 100.0869 g/mol
Mass = The number of moles × The molar mass
∴ The mass of CaCO₃ Jeeves needs to find = 0.7133 moles × 100.0869 g/mol ≈ 71.392 g
The mass of CaCO₃ Jeeves needs to find ≈ 71.392 grams.
Why do you think there is a need for three layers in a film
Answer:
When our tear film becomes unstable, symptoms of Dry Eye can occur. OUR TEAR FILM HAS THREE LAYERS. Our tear film is made up of three layers – an oil (lipid) layer, a water (aqueous) layer and a mucin layer. ... Its main purpose is to seal the tear film which helps reduce evaporation of our natural tears.
Will any of these properties change after a couple hours in the sun?
Answer:
you didnt show a picture, but if it just exposed then it will probably be a physical change
Explanation:
The downward movement of water through pores and other spaces in soil due to gravity is called____
A Iniltration
B evaporation
C soakation
D seepage
Answer:
A Infiltration
Explanation:
The downward movement of water through pore spaces and other spaces in soil due to gravity is called infiltration.
Infiltration is greatly due to the force of gravity forcing water through pore spaces downward.
The ground water recharge is also impacted by this downward motion of water. In areas where the surface of the soil is covered with concrete, infiltration is not possible. Soil water content is due to the movement of water by infiltration.Which equation is balanced in an acidic solution?
Answer:
I think C but it could be D
Explanation:
I would say go for C
How many hydrogen atoms are there in 2 molecules of C3H6?
Answer:
there are 12 hydrogen atoms in 2 molecules of C3H6
Explanation:
For work to be done on an object:
*
The work input must be equal to the work output
The energy input must be equal to the energy output
Only a force must be applied, moving the object is not required
The object has to move a distance when a force is applied to it
Answer:
The object has to move a distance when a force is applied to it
Explanation:
For work to be done on a body the force applied must move the body through a particular distance.
Work done = Force x distance
If no distance is moved by the force, no work is done.
Also, the angle between the force and the distance must be 0 to do the maximum work on the body.