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.
pleae help me I'm so confused
What is the velocity of a person that runs 40 km in 100 hours?
Answer:
0.4 km/h velocity is also the direction their going, in this case the person, that I'll name billy bob joe, is going in so yeh
Explanation:
give me brainliest?
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.
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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
Write complete electron configuration for each of the
following elements:
(a) scandium
(c) bromine
(b) cesium
(d) oxygen
Consider the picture of a gas pump. Which type of gasoline has the highest percentage of octane (the main component of gasoline)?
unleaded: 87 octane rating
mid-grade: 89 octane rating
premium: 91 octane rating
Answer:
premium: 91 octane rating
Explanation:
Octane number refers to the percentage or volume fraction of isooctane in a fuel.
The octane number gives a picture of how safe a fuel is for an engine. The higher the octane rating the lesser the tendency of the fuel to cause knocking of the engine.
The type of gasoline with the highest percentage of octane among the options is premium.
Which pair of compounds has the same empirical formula? C₂H₂ and C₆H₆ C₂H₆ and C₃H₆ C₂H₅OH and CH₃OH CH₃CHO and C₃COOH
Pair of compounds have the same empirical formula :C₂H₂ and C₆H₆
Further explanationGiven
Carbon compound
Required
The same empirical formula
Solution
The empirical formula is the smallest comparison of atoms of compound forming elements.
A molecular formula is a formula that shows the number of atomic elements that make up a compound.
(empirical formula) n = molecular formula
C₂H₂ and C₆H₆
Empirical formula CH
(CH)₂=C₂H₂
(CH)₆=C₆H₆
C₂H₆ and C₃H₈
C₂H₆: Empirical formula CH₃
C₃H₈: Empirical formula C₃H₈
C₂H₅OH and CH₃OH ⇒ Empirical formula
CH₃CHO: Empirical formula : CH₃CHO
CH₃COOH: Empirical formula CH₂O
Yo can someone help me answer this
Answer:
D
Explanation:
You need both, independant and dependant variables for a hypothesis.
Item 17 Which symbol represents a salt? C2H2 C6H12O6 KCl O2 Item 17 Which symbol represents a salt? C2H2 C6H12O6 KCl O2
Answer:
The symbol that represent a salt is CaCl2
Explanation:
The CaCI2 is the calcium chloride that an organic compound now a salt having a chemical formula i.e. CaCI2. Also it is non-color cyrstalline solid at the room temperature also it is highly soluble in the water
Therefore as per the given situation the symbol that represent a salt is CaCI2
This is the answer and the same is not provided in the given options
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.
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]
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.
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.
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!
_______________________________
The abnormally high boiling point of HF as compared to HCl is primarily due to intermolecular forces of attraction called
A) network bonds
B) electrovalent forces
C) hydrogen bonds
D) van der Waals forces
Answer:
C) hydrogen bonds
Explanation:
The abnormally high boiling point of HF compared to HCl is primarily due to the intermolecular forces called hydrogen bonds.
Hydrogen bonds are intermolecular forces of attraction between polar molecules in which a hydrogen atom is directly joined to a highly electronegative atom (oxygen, nitrogen or fluorine).
Hydrogen bonds are very strong force of attraction compared to dipole - dipole attraction that holds the HCl together.
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.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
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
The article states that amplitude plays a role in what happens to a sound
wave. Why do you think higher amplitude waves are more often
transmitted while lower amplitude waves are reflected or absorbed?
Answer:
Sound waves travel through matter
Explanation:
Higher amplitude sound waves are more likely to be transmitted through matter instead of reflected. Lower amplitude sound waves are more likely to be reflected or absorbed, resulting in a lack of an echo. Sound can travel through air, water, and solids
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:
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 true about the electron configurations of the noble gases?
A) The highest occupied s and p shells are completely filled.
B) The highest occupied s and p shells are partially filled.
C) The electrons with the highest energy are in a d sublevel.
D) The electrons with the highest energy are in an f sublevel.
How are gases and liquids different from each other
Answer:
Gases, liquids, and solids are all made up of atoms, molecules, and/or ions, but the behaviors of these particles differ in the three phases. Gas is well separated with no regular arrangement. liquid are close together with no regular arrangement. solid are tightly packed, usually in a regular pattern.
Explanation:
- Is energy absorbed or released by a material during the phase change from a solid to a liquid?
A)Absorbed
B)Released
Answer:
A) Abosrbed
Explanation:
The change is endothermic, meaning the material absorbs energy when it changes its phase from a solid to a liqiud.
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.
Why is the use of high-frequency radio waves a beneficial technological advancement
for humans? Explain.
A. They have the best penetration.
B. They carry more information.
C. They travel over longer distances.
D. They do not require mediums to transmit.
I
Answer:
I think It's C
Explanation:
due to higher waves can get easy transfers and receive those signals for most things, such as radios, TVs, phone signals etc etc
The use of high-frequency radio waves, a beneficial technological advancement for humans because they travel over longer distances.
What is frequency ?The frequency of a repeated event is its number of instances per unit of time. In certain cases, it is also referred to as temporal frequency or ordinary frequency to underline differences with spatial and angular frequencies, respectively.
The number of waves that pass a specific place in a predetermined period of time is known as the wave frequency. The hertz (Hz) is the SI unit for wave frequency, where 1 hertz is equivalent to 1 wave crossing a fixed point in 1 second.
The vibrations that created the wave had the same frequency as the wave itself. For instance, you need to move a rope up and down faster to produce a wave with a greater frequency.
Thus, option C is correct.
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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 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:
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%
How many hydrogen atoms are there in 2 molecules of C3H6?
Answer:
there are 12 hydrogen atoms in 2 molecules of C3H6
Explanation: