Answer:
A. The color change from blue to green happens in nature.
Explanation:
The color change is an indicator of a chemical reaction that has occurred. Although color changes are not necessarily good diagnostic tool to measure if a chemical reaction has occurred or not.
In this reaction, color changes is quite an effective tool Chemical changes usually involves the formation of a new product from the chemical reaction. Also, the steps are not easily reversible.For this reaction, color change is the most appropriate signal for a chemical change.The evidence that shows that a chemical reaction has taken place is the disappearance of the steel wool shows that a new substance has formed.
The electrochemical series is arrangement of elements in order of decreasing reactivity. It is important to note that the elements that are high up in the electrochemical series can displace the elements that are lower in the series from their aqueous solution.
Steel contains iron which lies above copper in the electrochemical series hence a chemical change occurs when steel dissolves in the copper solution.
Hence, the evidence that shows that a chemical reaction has taken place is the disappearance of the steel wool shows that a new substance has formed.
Learn more: https://brainly.com/question/8646601
which was an important part of dalton's atomic model
How many significant figures are in the number 4.02 x 10^-9 ?
Answer:
3 sig figs
Explanation:
If the concentration of Sn2+ in the cathode compartment is 1.10 M and the cell generates an emf of 0.22 V , what is the concentration of Pb2+ in the anode compartment?
Answer:
[Pb] = 1.1*10^-8
Explanation:
The Eo values of the half cell reaction of the following are
Pb2+ + 2e- ==> Pb . . .Eo = -0.13 V
Sn2+ + 2e- ==> Sn . . .Eo = -0.14 V
Sn+2 is at cathode(reduction)compartment and Pb+2 is at anode(oxidation) compartment.
the overall reaction will be
Pb ==> Pb2+ + 2e- (oxidation) Eo = +0.13 V
Sn2+ + 2e- ==> Sn (reduction) Eo = -0.14 V
----------------------------------------------------------------------
Pb + Sn2+ ==> Pb2+ + Sn Eo cell = -0.01 V
Qcell = [Pb+2] / [Sn+2] ( pure Sn , Pb do not appear in Q
Ecell = Eo -0.059/n* logQ
0.22 = -0.0.1 - 0.059/2 logQ
0.23 = -0.0295logQ
LogQ= -7.796
Q = 10^-7.796≈ 1/10^8
[Pb+2] / [Sn+2] = 1/10^8
[Pb] = 1.1*10^-8
GUYS I NEED HELP WITH THIS ASSIGNMENT MY LAST ASSIGNMENT FOR THE DAY
1. What are the reactants? What are the products? Use the reaction below (2pts)
Na + Cl2 → NaCl
2. Why do chemical reactions need to be balanced? (2pt)
3. In order to balance the following reaction, I need to add more Chlorine atoms to the product side. Would the highlighted answer be a correct way of adding more Chlorine atoms? Why or why not? (2pt)
Balanced: Na + Cl2 → NaCl2
4. Given the following reactions, what does the coefficient 2 represent for 2KI? (2pt)
Cl2 + 2 KI → 2 KCl + I2
Answer:
the reactants are na and cl2 the products is the combination nacl --the law of conservation of matter keeps reactions balanced. No you would not be adding more atoms that is what the first combo is. The coefficient 2 stands for 2 atoms of KL
Explanation:
Screenshot very easy
1. option B
2. ground state Fe : [Ar] 4s² 3d⁶
Further explanationAufbau rule
Electrons occupy orbitals of the lowest energy level
Charging electrons in the sub-shell uses the following sequence:
1s², 2s², 2p⁶, 3s², 3p⁶, 4s², 3d¹⁰, 4p⁶, 5s², 4d¹⁰, 5p⁶, 6s², etc.
So the correct choice of answer is B.
Ground state is the state of electrons filling skins with the lowest energy levels.
Excited state is the state of electrons which occupy a higher energy level
The atomic number of Fe = 26, so electrons=26
Ground state configuration of Fe : [Ar] 4s² 3d⁶ or
1s², 2s², 2p⁶, 3s², 3p⁶, 4s², 3d⁶
Answer:
d
Explanation:
____causes movement of an object,whereas____is the work done ✔️ on an object in given amount of time
Answer:
the first answer is force and the second one is power
Explanation:
Force is what causes movement
Answer:
force & power
Explanation:
Explain how you know the charge of a nickel ion given a formula and a name.
Can someone help me pls
What happens to water when it freezes
A: It’s mass increases
B: its mass decreases
C: Its density increases
D: Its density decreases
Answer:
D. It's density decreases
I'm not sure ok.. Ask an adult for making sure
BRAINLIEST IF RIGHT
A group of students observe their teacher modeling how a river carries sediments downstream to eventually create a delta. Which of the following scientific questions can best be answered by this model?
A.
What is the cause and effect relationship between weathering and cementation?
B.
How does chemical weathering of rocks in a river create a delta?
C.
What is the cause and effect relationship between erosion and deposition?
D.
How does a river weather rocks into sediments?
Answer:
C What is the cause and effect relationship between erosion and deposition?
Explanation:
i hope this help
How many moles of Cu do you need to react with 12 moles of O2?
2Cu(s) + O2(g) 2CuO(s)
Answer:
24 mol Cu
General Formulas and Concepts:
Chemistry
StoichiometryExplanation:
Step 1: Define
RxN: 2Cu (s) + O₂ (g) → 2CuO (s)
Given: 12 moles O₂
Step 2: Stoichiometry
[tex]12 \ mol \ O_2(\frac{2 \ mol \ Cu}{1 \ mol \ O_2} )[/tex] = 24 mol Cu
Step 3: Check
We are given 2 sig figs.
Our final answer is in 2 sig figs, so no need to round.
what is covalent bond
Answer:
A covalent bond is a chemical bond that involves the sharing of electron pairs between atoms.
Explanation:
Imagine you have a radioactive sample containing both virtualium and decayed atoms of virtualium. After analysis you find it contains 10 atoms of virtualium and 40 decayed atoms . How old is your sample? Hint you must use the half life of virtualium determined earlier. BTW the half life of virtualium is 12
Answer:
COULD WE PLEASE GET THIS ANSWER?????
Explanation:
help help help help help help help help help help please!!! worth 20 points please helppppp!!!!
Explanation:
here
Al is 2
so is 6
and more you can do it
0.50g of a volatile liquid was introduced
into a globe sf 1000ml capacity. The globe
was heated to 91°C, so that all the liquid
vapourised exerted
a pressure of 190 mmHg.
Calculate the molecular mass of the lliquid.
Answer:
59.52g/mol
Explanation:
This question can be answered using the formula;
PV = nRT
Where;
P = pressure (atm)
V = volume (L)
R = gas constant (0.0821 Latm/molK)
T = temperature (K)
From the information provided:
P = 190mmHg = 190/760 = 0.25atm
V = 1000ml = 1000/1000 = 1L
n = number of moles = ?
T = 91°C = 91 + 273.15 = 364.15K
PV = nRT
0.25 × 1 = n × 0.0821 × 364.15
0.25 = 29.8967n
n = 0.25/29.8967
n = 0.0084mol
Mole = mass/molar mass
Molar mass = mass/mole
Molar mass = 0.50/0.0084
Molar mass = 59.5238
Hence, the molecular mass of the liquid is 59.52g/mol
The number of atoms of each element before the reaction and the number of
atoms of each element after the reaction must be _______________
A.) 2
B.) 12
C.) 32
D.) 40
Answer:
a
Explanation:
6 times 3 =18
01:45:05 Which statement describes how diffusion works? Molecules always move from inside of the cell to outside of the cell. Molecules always move from areas of high concentration to low concentration. Molecules always move from areas of low concentration to high concentration. Molecules always move from of outside the cell to inside of the cell.
Answer:
Molecules always move from areas of high concentration to low concentration.
Explanation:
The correct answer to how diffusion works would be that molecules always move from areas of high concentration to low concentration.
Diffusion is generally defined as the movement of molecules - solid, liquid, or gases - from the region of higher concentration of the molecule to the region of lower concentration of the same molecule. The net movement of molecules continues until an equilibrium is established between the two sides.
What are the products in a chemical reaction?
A. The chemical formula of the substances
B. The new substances that are produced
C. The substances that interact
D. What is left over after the reaction
Which term refers to the sum of the kinetic energy of all the particles in an object?A.Potential energyB.Thermal energyC.TemperatureD.Heat
plzz hurry
Answer:
It’s the other answer, thermal energy
Explanation:
I hope y’all get a good grade
Thermal energy refers to the sum of the kinetic energy of all the particles in an object. Hence, the correct option is B.
Thermal energy is a form of internal energy associated with the random motion and vibrations of atoms and molecules within a substance. It is directly related to the temperature of the object, as the temperature is a measure of the average kinetic energy of the particles. The higher the temperature, the greater the thermal energy of the object.
Potential energy (A) refers to the energy that an object possesses due to its position or state, such as gravitational potential energy or elastic potential energy.
Temperature (C) is a measure of the average kinetic energy of the particles in a substance and is not the sum of the kinetic energy of all the particles. However, it is related to thermal energy as it provides information about the average kinetic energy.
Heat (D) refers to the transfer of thermal energy from one object to another due to a temperature difference. It is not the sum of the kinetic energy of the particles in an object but rather the energy transfer between objects with different temperatures.
Learn more about Thermal energy from the link given below.
https://brainly.com/question/3022807
#SPJ2
Can someone plezzzz help
Answer:
CH₄ + 2O₂ → 2H₂O + CO₂
Explanation:
From the given problem;
White balls = hydrogen
Black balls = carbon
Gray balls = oxygen
Equation of the reaction:
1 carbon atom surrounded by 4 hydrogen + 2 oxygen molecules gives two hydrogen atoms bonded to one oxygen + 1 carbon atom bonded to two oxygen
CH₄ + 2O₂ → 2H₂O + CO₂
The reaction above is balanced.
what two subatomic particles have to be different in order to have an ion?
A)Protons and electrons
B)Protons and neutrons
C)Neutrons and electrons
Answer:
A)Protons and electrons
Explanation:
An atom consist of electron, protons and neutrons. Protons and neutrons are present with in nucleus while the electrons are present out side the nucleus.
All these three subatomic particles construct an atom. A neutral atom have equal number of proton and electron. In other words we can say that negative and positive charges are equal in magnitude and cancel the each other. For example if neutral atom has 6 protons than it must have 6 electrons. The sum of neutrons and protons is the mass number of an atom while the number of protons are number of electrons is the atomic number of an atom.
when an atom lose or gain the electron ions are formed and number of protons and electrons no longer remain the same.
For example:
An atom of sodium when lose one electron it form positive ion. The number of electrons became 10 and number of protons remain 11.
Na → Na⁺ + 1e⁻
What happens to rock during subduction please help I will give you Brainlyest
Answer: Here is the answer!! :)
Explanation:
A subduction zone is a region of the earth's crust where one tectonic plate moves under another tectonic plate; oceanic crust gets recycled back into the mantle and continental crust gets created by the formation of arc magmas. ... This water lowers the melting point of mantle rock, initiating melting.
Here is a graph to understand it better!:)
What are some different types of stimuli?
Answer:
Mechanical, thermal,chemical
Explanation:
Answer:
chemical, temperature, pressure, and light
Explanation:
two hydrogens atoms and one oxygen atom together are?
Answer:
h20 water is the answer
If the Earth rotated in the opposite direction, what would most likely occur? Select one
a.There would be more days in each year.
b.The phases of the Moon would last longer. c.The Sun would rise in the west.
d.The seasons would be reversed.
Answer:
,jgkgchgchgcchgchg
Explanation:
What can happen during a physical change
Answer:
Physical changes occur when objects or substances undergo a change that does not change their chemical composition. This contrasts with the concept of chemical change in which the composition of a substance changes or one or more substances combine or break up to form new substances.
Explanation:
In a lava lamp, a waxy substance rises and falls repeatedly. What causes the waxy substance to rise? Check all that apply. The waxy substance is cold. The waxy substance is warm. The waxy substance is less dense than the surrounding liquid. The waxy substance is more dense than the surrounding liquid. Convection is occurring.
Answer:
The waxy substance is warm.
The waxy substance is less dense than the surrounding liquid.
Convection is occurring.
Explanation:
Convection involves heat transfer by the actual movement of the particles of a substance.
When the wax is heated, the waxy substance becomes warm and rises in the lamp. The warm waxy substance is less dense than the surrounding liquid, this process of rising and falling is as a result of convection occurring in the lava lamp.
Answer:
The person above (or below) me is correct, the answer is:
B.) The waxy substance is warm.
C.) The waxy substance is less dense than the surrounding liquid.
E.) Convection is occurring.
Explanation:
I did the assignment on Edge, 2022.
(See the attachment below.)
Hope this helped, good luck on your quiz! <3
If water with a mass of 25.0 grams freezes in a closed system such as a closed glass jar, what is the mass of the formed ice after the water completely freezes?
A group of students conducted an experiment to find out what happens to the force of magnetism between two magnets as the distance between them increases. They used the equipment you see in the illustration. They
placed spacers between the magnet in the cup and the magnet on the post to increase the distance between them. They used washers as units to measure how much force it took to pull the two magnets apart.
Answer:
40
Explanation:
Porque yo creo que asi ) :
50mL of ethanol (density=0.79 g/mL) is dissolved by 400 mL of water. What is the concentration of ethanol in this solution?
The concentration of ethanol in this solution : 2.14 M
Further explanationMolarity is a way to express the density of the solution
Molarity shows the number of moles of solute in every 1 liter of solute or mmol in each ml of solution
[tex]\tt \large{\boxed{\bold {M ~ = ~ \dfrac {n} {V}}}[/tex]
Where
M = Molarity
n = Number of moles of solute
V = Volume of solution
Ethanol(C₂H₅OH) MW =46,06844 g/mol[
mass of solute (Ethanol)[tex]\tt 50\times 0.79=39.5~g[/tex]
mol of Ethanol[tex]\tt \dfrac{39.5}{46.06844}=0.8574[/tex]
molarity[tex]\tt \dfrac{0.8574}{0.4}=2.14~M[/tex]