Answer:
The elements in each group have the same number of electrons in the outer orbital. Those outer electrons are also called valence electrons. They are the electrons involved in chemical bonds with other elements
Explanation:
Elements are the simplest complete chemical substances. Each element corresponds to a single entry on the periodic table. An element is a material that consists of a single type of atom. Each atom type contains the same number of protons.
in a hypothetical element ,two energy levels are separated by an energy of 282kj mol-1 . what wavelength of light (in nma) is evolved for an electron to change between these two levels?
Answer:
7.05 × 10⁻²² nm
Explanation:
Step 1: Given and required data
Energy evolved when a mole of electrons changes between the 2 levels (E): 282 kJPlanck's constant (h): 6.63 × 10⁻³⁴ J.sSpeed of light (c): 3.00 × 10⁸ m/sStep 2: Calculate the wavelength (λ) of the light evolved
We will use Planck-Einstein's relation.
E = h × c/λ
λ = h × c/E
λ = (6.63 × 10⁻³⁴ J.s) × (3.00 × 10⁸ m/s)/(282 × 10³ J) = 7.05 × 10⁻³¹ m
We will convert λ to nm using the conversion factor 1 m = 10⁹ nm.
7.05 × 10⁻³¹ m × 10⁹ nm/1 m = 7.05 × 10⁻²² nm
is this correct im just asking because my little brother not sure for his answer
Plz help plz help me will mark Brainly
Answer:
Greenhouse gases absorb some of the energy and trap it in the lower atmosphere. Less heat radiates into space, and Earth is warmer. Many greenhouse gases occur naturally. Carbon dioxide, methane, water vapor, and nitrous oxide are naturally present in Earth's atmosphere. Since some of the extra energy from a warmer atmosphere radiates back down to the surface, Earth's surface temperature rises.
Hope this helped! :)
Why would you want to slow down a chemical reaction?
Answer:
We often want to decrease the rates of certain reactions rather than speeding them up. For example, to prolong the shelf lives of certain foods, the chemical reactions by which they spoil must be slowed down.
If oxygen gas at 118 °C and 10.8 atm was heated to 948 °C, what would the new
pressure be?
Answer: The new pressure is 1.34 atm.
Explanation:
Given: [tex]P_{1}[/tex] = 10.8 atm, [tex]T_{1} = 118^{o}C[/tex]
[tex]P_{2}[/tex] = ?, [tex]T_{2} = 948^{o}C[/tex]
Formula used to calculate the new pressure is as follows.
[tex]\frac{P_{1}}{T_{1}} = \frac{P_{2}}{T_{2}}\\\frac{10.8 atm}{118^{o}C} = \frac{P_{2}}{948^{o}C}\\P_{2} = 1.34 atm[/tex]
Thu, we can conclude that the new pressure is 1.34 atm.
how many moles are in 89 grams of Pb(CH3COO)4
Answer:
0.20 moles of Pb(CH3COO)4
Explanation:
89g Pb(CH3COO)4 x 1 mol Pb(CH3COO)4 / 443.376 g Pb(CH3COO)4
= 0.20 moles of Pb(CH3COO)4
One mole of lead acetate weighs 443.29 g. Then, 89 grams of lead acetate contains 0.20 moles of Pb (CH₃COO)₄.
What is one mole ?One mole of a substance is its amount containing 6.02 × 10²³ atoms or molecules. This number is called Avogadro number. One mole of every elements contains Avogadro number of atoms.
Similarly one mole of every compound contains 6.02 × 10²³ molecules. The mass of one mole of compound is called its molar mass. The number of moles of the compound can be determined by dividing the given mass by molar mass.
Molar mass of lead acetate = 443.29 g/mol
given mass = 89 grams
then , no.of moles = weight/molar mass
n = 89 g/ (443.29 g/mol) = 0.20 moles
Therefore, the number of moles of Pb (CH₃COO)₄ in 89 g is 0.20 moles.
Find more on Avogadro number:
http://brainly.com/question/11907018
#SPJ5
Find the % composition for each element in Zinc Chlorate
Answer:
chlorine ~ 30%
zinc ~ 28%
oxygen ~ 41%
Explanation:
How many grams of carbon dioxide will be produced if 76.4 grams of
C2H3Br3 reacted with 49.1 grams of O2? How many grams of the
excess reactant will be left after the reaction is over? Consider the
equation: C2H3Br3+O2 -> CO2+H2O+Br2
Answer:
Assuming that all of the oxygen is used up, 1.53×4111.53×411 or 0.556 moles of C2H3Br3 are required. Because there are only 0.286 moles of C2H3Br3 available, C2H3Br3 is the limiting reagent.
Limiting Reagent What is the limiting reagent if 76.4 grams of C2H3Br3 were reacted with 49.1 grams of O2? C2H3Br3 + 11O2 → 8CO2 + 6H2O + 6Br2 SOLUTION Using Approach 1: A. 76.4g × (1 mol/ 266.72 g) = 0.286 moles C2H3Br3 49.1g × (1 mole/ 32 g) = 1.53 moles O2 B.
Explanation:
MRK ME BRAINLIEST PLZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZ
https://chem.libretexts.org/Bookshelves/Introductory_Chemistry/Map%3A_Introductory_Chemistry_(Tro)/08%3A_Quantities_in_Chemical_Reactions/8.04%3A_Limiting_Reactant_and_Theoretical_Yield
Learn more about
https://brainly.com/question/20454467
to make a large quantity of a 5% solution of HCl but only have 25mL HCl. what volume of 5% solution can be made from this volume of HCl?
Answer:What is the volume of 37% HCl?
If however you meant to say 0.025M and assuming you want to prepare 1L solution then the volume of 37% HCl needed should be= (1000 X 0.025X 36.5)/ (37X1.19X10)=2.07 mL diluted to 1 L using DI water. Good day. If you want 0.025 mole HCl solution, you should take a 2.09 ml of your acid.
Explanation:To prepare 5% solution from this acid; simply take 5 ml. of the acid and add it to 95 ml of distilled water.You get a 5%HCl solution. By the way, Hydrogen Chloride is the name designated to the gas evolved from HCl acid
To determine the volume of a 5% solution that can be made from 25 mL of HCl, we need to use the equation: C1V1 = C2V2
Where:
C1 = Initial concentration of HCl
V1 = Initial volume of HCl
C2 = Final concentration of the solution (5% or 0.05 in decimal form)
V2 = Final volume of the solution (unknown)
What is HCl?HCl stands for hydrochloric acid. It is a strong, highly corrosive acid that is commonly used in various industrial, laboratory, and chemical applications. In its pure form, hydrochloric acid is a colorless liquid with a pungent odor. It is composed of hydrogen (H) and chlorine (Cl) and is known for its acidic properties.
Let's plug in the known values:
C1 = 100% (since the initial HCl is undiluted)
V1 = 25 mL
C2 = 5% or 0.05
V2 = Unknown
Solving for V2:
C1V1 = C2V2
(1)(25 mL) = (0.05)(V2)
25 mL = 0.05V2
Divide both sides by 0.05 to isolate V2:
V2 = 25 mL / 0.05
V2 = 500 mL
Therefore, from 25 mL of HCl, you can make a 500 mL solution with a concentration of 5%.
Learn more about HCl at:
https://brainly.com/question/29204122
#SPJ2
The primary structure of a protein is determined by
A. The order of amino acids in the protein.
B. The amino acid composition.
C. The hydrogen bonding that gives the protein three dimensional shape.
D. The intertwining of protein molecules to form a “functional” protein.
Answer: I believe the answer is A. The order of amino acids in the protein.
Explanation:
For each event stated below, indicate how the concentration of each species in the chemical equation will then change to reach equilibrium.
2CO(g) + O2(g) ⇌ 2CO2(g)
a. increasing the concentration of CO
b. decreasing the amount of O2
c. decreasing the the volume of the system
Answer:
See Explanation
Explanation:
When a constraint such as a change in temperature, concentration or pressure is imposed on a reaction system in equilibrium, the system will readjust itself in such a way as to annul the constraint. This readjustment occurs when the equilibrium position shifts towards the left or right in order to annul the constraint.
a. increasing the concentration of CO: When the concentration of CO is increased, the equilibrium position shifts to the right in order to annul the constraint. This means that more CO2 is produced in the system while the concentration of CO and O2 are decreased until equilibrium is reestablished.
b. decreasing the amount of O2: When the amount of O2 is decreased, the equilibrium position will shift to the left and more CO and O2 are produced while the concentration of CO2 decreases until equilibrium is reestablished.
c. decreasing the the volume of the system: When the volume of the system is decreased, the equilibrium position shifts towards the right hand side where there is less total volume. Hence the concentration of CO and O2 decreases while the concentration of CO2 increases.
PLZ ANSWER QUICK I AM IN TIMER HELP WILL GIVE BRAINLIEST
Which is greater, the moon's period of rotation or its period of revolution?
They are equal.
the moon's revolution period around Earth
Neither are known.
the moon's rotational period
Answer:
B
Explanation:
Phosphorus (P4) and hydrogen gas can combine to form phosphine (PH3), a toxic gas with the odor of rotting fish. Complete and balance the equation for this chemical reaction.
Answer:
P₄ + 6 H₂ ⇒ 4 PH₃
Explanation:
Let's consider the unbalanced reaction that takes place when phosphorus reacts with hydrogen to form phosphine. This is a synthesis reaction.
P₄ + H₂ ⇒ PH₃
We will balance this reaction using the trial and error method. First, we will balance P atoms by multiplying PH₃ by 4.
P₄ + H₂ ⇒ 4 PH₃
Finally, we get the balanced equation by multiplying H₂ by 6.
P₄ + 6 H₂ ⇒ 4 PH₃
2) Choose the best answer. Which type of reaction is this? NaOH + H2O → Na+ + OH strong base dissociation strong acid dissociation weak base dissociation neutralization weak acide dissociation
Answer:
strong Base Dissociation
Explanation:
NaOH is baseNaOH is strong base that means strong acids ionizes almost completely when dissolved in water.When looking across the periodic table from left to right, which of these groups are the first to contain nonmetals?
group 2
group 7
group 14
group 18
Answer:
The first group to contain a non-metal is Group 18.
Draw a schematic diagram of a circuit with an output device, a energy source and a controller.
Answer:
ch∪pαpi munαn0?
Explanation:
7. What is the mass of a piece of copper (Cu) that undergoes a 25.0 °C
temperature change with the loss of 428 J of energy?
Answer:
0.0428 kg or 42.8 g
Explanation:
Applying,
Q = cmΔt.............. Equation 1
Where Q = heat lost of heat gained, c = specific heat capacity of copper, m = mass of copper, Δt = temperature change.
make m the subject of the equation above
m = Q/cΔt.................. Equation 2
From the question,
Given: Q = 428 J, Δt = 25 °C
Constant: c = 400 J/kg.°C
Substitute these values into equation 2
m = 428/(25×400)
m = 0.0428 kg
m = 42.8 g
Products will form faster if___
A) temperature is decreased
B) the reaction is not stirred
C) the particle size of the reactants are larger
D) concentration of the reactants are increased
Answer:
C(btw this could be wrong)
Explanation:
Answer:
B is the answer
Explanation:
Determine the type of reaction: AgNO3 + Cu --> Cu(NO3)2 + Ag
Explanation:
Cu + 2 AgNO3 → Cu(NO3)2 + 2 Ag
Cu is oxidized
Ag+ is reduced
Cu is the reducing agent
To solve such this we must know the concept of displacement reaction. The balanced reaction of silver nitrate with copper is of displacement type of reaction.
AgNO[tex]_3[/tex] + Cu [tex]\rightarrow[/tex] Cu(NO[tex]_3[/tex])[tex]_2[/tex] + Ag
What is Balanced equation?Balanced equation is the one in which the total number of atoms of a species on reactant side is equal to the total number of atoms on product side. The mass of the overall reaction should be conserved. There are so many types of chemical reaction reaction like combination reaction, displacement reaction.
The reaction between silver nitrate and copper is example of displacement reaction. Copper displaces silver from silver nitrate. to form copper nitrate.
Therefore, the balanced equation is of displacement type of reaction.
AgNO[tex]_3[/tex] + Cu [tex]\rightarrow[/tex] Cu(NO[tex]_3[/tex])[tex]_2[/tex] + Ag
Learn more about the balanced equation, here:
https://brainly.com/question/7181548
#SPJ2
the mass concentration the mass concentration for a solution containing 45 g of calcium carbonate is 100 cm3
Answer: The mass concentration for a solution containing 45 g of calcium carbonate for 100 [tex]cm^{3}[/tex] is 0.045 M.
Explanation:
Given: Mass of calcium carbonate = 45 g
Volume = [tex]100 cm^{3}[/tex]
Convert [tex]cm^{3}[/tex] into L as follows.
[tex]1 cm^{3} = 0.001 L\\100 cm^{3} = 100 cm^{3} \times \frac{0.001 L}{1 cm^{3}}\\= 0.1 L[/tex]
Moles of calcium carbonate (molar mass = 100 g/mol) is as follows.
[tex]No. of moles = \frac{45 g}{100 g/mol}\\= 0.45 mol[/tex]
Molarity is the number of moles of solute present in a liter of solution.
Hence, molarity (or mass concentration) of given solution is calculated as follows.
[tex]Molarity = \frac{no. of moles}{Volume (in L)}\\= \frac{0.45 mol}{0.1 L}\\= 0.045 M[/tex]
Thus, we can conclude that the mass concentration for a solution containing 45 g of calcium carbonate for 100 [tex]cm^{3}[/tex] is 0.045 M.
Definition: These are the layers of rock or soil that are distinguishable from other layers that have been
laid down upon one another over the history of the earth.
01)
Term: Type term here
Strata are the layers of rock or soil that are distinguishable from other layers that have been laid down upon one another over the history of the earth.
What is a Strata?A strata is the horizontal layer of rocks or sedimentary rocks that are laid upon another or arranged one on top of another that is separated by adjacent beds planes or layers.
Therefore, Strata are the layers of rock or soil that are distinguishable from other layers that have beenlaid down upon one another over the history of the earth.
Learn more about strata below.
https://brainly.com/question/25817019
True or False: A higher vapor pressure (evaporates easily) corresponds to strong intermolecular forces.
A cylinder of gas with a pressure of 8.0 atm is heated from 300. K to 600. K. What will the new pressure of the gas be?
Answer:
[tex]P_2=16atm[/tex]
Explanation:
Hello there!
In this case, according to the given information, we can infer we need to use the Gay-Lussac's equation it order to understand this pressure-temperature relationship as shown below:
[tex]\frac{P_1}{V_1}=\frac{P_2}{V_2}[/tex]
Thus, we solve for P2 and plug in P1, T1 and T2, to obtain:
[tex]P_2=\frac{P_1T_2}{T_1}\\\\P_2=\frac{8atm*600K}{300K}\\\\P_2=16atm[/tex]
Regards!
Consider an electron with charge −e−e and mass mmm orbiting in a circle around a hydrogen nucleus (a single proton) with charge +e+e. In the classical model, the electron orbits around the nucleus, being held in orbit by the electromagnetic interaction between itself and the protons in the nucleus, much like planets orbit around the sun, being held in orbit by their gravitational interaction. When the electron is in a circular orbit, it must meet the condition for circular motion: The magnitude of the net force toward the center, FcFcF_c, is equal to mv2/rmv2/r. Given these two pieces of information, deduce the velocity vvv of the electron as it orbits around the nucleus. Express your answer in terms of eee, mmm, rrr, and ϵ0ϵ0epsilon_0, the permittivity of free space.
Answer:
Explanation:
The net force on electron is electrostatic force between electron and proton in the nucleus .
Fc = [tex]\frac{1}{4\pi\epsilon} \times \frac{e\times e}{r^2}[/tex]
This provides the centripetal force for the circular path of electron around the nucleus .
Centripetal force required = [tex]\frac{m\times v^2}{r}[/tex]
So
[tex]\frac{m\times v^2}{r}=\frac{1}{4\pi\epsilon} \times \frac{e\times e}{r^2}[/tex]
[tex]v^2=\frac{e^2}{4\pi \epsilon m r}[/tex]
[tex]v=(\frac{e^2}{4\pi \epsilon m r})^{\frac{1}{2} }[/tex]
If you have 1.82 moles of mercury (Hg), how many grams of mercury do you have?
Answer:
182
Explanation:
1 hectogram (hg) = 100 grams (g)
1.82 x 100 = 182
Answer both of these true or false correctly
brainliest if correct
Answer:
There both true.
Explanation:
Hope this helps
Answer:
The first one is True
The second one is false
Explanation:
You can find the speed on a distance-versus-time graph by finding the slope of the line.
True
False
A reaction that produces great heat for welding and incendiary bombs
is the "thermite" reaction, Fe2O3 (s) + 2Al(s) Al2O3 (s) + 2Fe (s)
How many moles of iron form by the complete reaction of
7.1 9 of iron (III) oxide ?
Answer:
7.19 g of Fe2O3 will produce 0.092 mole of iron
Explanation:
One mole of Fe2O3 reacts with 2 mole of Aluminum to produce one mole of Al2O3 and 2 mole of iron.
Mass of one mole of Fe2O3 = 159.69 g/mol
Thus, 159.69 g/mol of Fe2O3 produces two mole of Fe
7.19 g of Fe2O3 will produce
[tex]\frac{2}{156.9} * 7.19\\= 0.092[/tex]moles of iron
Which of the following does NOT represent a balanced reaction?
Answer:
letter D i thinkExplanation:
correct me if im wrong
Which particles appear in equal numbers in all uncharged atoms? Proton, Neutron, Electron, None
Answer:
In an uncharged atom, the number of protons is always equal to the number of electrons. Apr 24, 2017
Explanation:
Neutron: An uncharged particle found in the nucleus of an atom.
There is only one stable atom that does not have neutrons. It is an isotope of the element hydrogen called protium. Protium, which contains a single proton and a single electron, is the simplest atom.