Which of the following atoms has the largest atomic radius? Provide an explanation
a Hydrogen
b. Sodium
C Lithium
d Rubidium
Answer:
d Rubidium
Explanation:
The atomic radius of an atom is the distance from the center of the nucleus to its outermost electron.
The atomic radius of elements varies in the periodic table, it increases as you go down in a group and decreases along the period from left to right.
All the elements listed: Hydrogen, Sodium, Lithium and Rubidium belong to the same group in the periodic table (group 1), Since atomic radius increases from top to bottom in a group, Rubidium has the largest atomic radius.
At what temperature does the solid start meltin
-20°C
0°C
20"
80°C
Answer:
0 C.
Explanation:
Help!
A student dissolves 1 gram of sugar in 10 grams of water. She then determines the mass of the solution. What is the mass of the dissolved sugar and water?
a. less than 11 grams
b. more than 11 grams
c. 11 grams
d. It is not possible to tell from the data
Answer:
11 grams
Explanation:
Which type of reaction is described by the following equation Na2O (s) + 2CO2 (g) + H2) (g) Produces 2 NaHCO3 (s)
Answer:
If the reaction is going from left to right it would be synthesis, if going right to left it would be decomposition.
Explanation:
Na2O (s) + 2CO2 (g) + H2O (g) = 2 NaHCO3 (s)
Left Side
Na = 2
O = 6
C = 2
H = 2
Right Side
Na = 2
O = 6
C = 2
H = 2
Ok so is balanced already, though initial equation in question had an error in regards to the left hand side the ) should have been an O.
Hmm
Na2O (s) + 2CO2 (g) + H2O (g) = 2 NaHCO3 (s)
If it was going from right to left would be decomposition
But going from left to right it would be synthesis
What is the energy of an electromagnetic wave with a frequency of 8 x 10^12
Hz?
A. 4.2 x 10-22 J
B. 2.4 x 1021 J
C. 1.59 x 10-12
D. 5.3 x 10-21 J
Answer:
Energy, [tex]E=5.3\times 10^{-21}\ J[/tex]
Explanation:
It is required to find the energy of an electromagnetic wave with a frequency of [tex]8\times 10^{12}\ Hz[/tex]. The energy of a wave in terms of its frequency is given by :
[tex]E=h\nu[/tex]
[tex]\nu[/tex] = frequency of em wave
[tex]E=6.63\times 10^{-34}\times 8\times 10^{12}\\\\E=5.3\times 10^{-21}\ J[/tex]
So, the energy of an electromagnetic wave is [tex]5.3\times 10^{-21}\ J[/tex]
Answer:
D. [tex]5.3 * 10^-21 J[/tex]
Assign an oxidation number to each element in the reaction.
CO(g) + 2H2(g)
CH3OH(g)
In CO, the oxidation number of C is
and that of O is
In H2, the oxidation number of H is
In CH3OH, the oxidation number of C is
that of O is
and that of H is
DONE
Answer:
In CO, the oxidation number of carbon is +2 and that of oxygen is -2
In H2 the oxidation number of hydrogen is zero
In CH3OH, the oxidation state of carbon is -2, that of hydrogen is +1 and that of oxygen is -2
Explanation:
The oxidation number of an element in any compound is defined as the electrical charge that the element appears to have as determined by a set of arbitrary rules. These rules make it possible to calculate the oxidation number of an atom in a compound given the oxidation numbers of other atoms in the same compound.
In CO, the oxidation number of carbon is +2 and that of oxygen is -2
In H2 the oxidation number of hydrogen is zero
In CH3OH, the oxidation state of carbon is -2, that of hydrogen is +1 and that of oxygen is -2
The following half-reaction can be balanced in acidic solution:
N2O5 --> NH4+
How many electrons appear in the balanced equation?
A. 13e-
B. 14e-
C. 16e-
D. 18e-
Answer:
None of them, answer seems to be 24 unless I messed up
Explanation:
How many electrons appear in the balanced equation
What the heck do they mean, do they mean transferred?
N2O5 --> NH4+
Left Side
N 5+ Electrons 2 in central shell, 5 in outer
O 2- Electrons 2 in central shell, 6 in outer
Right Side
H 1+ Electrons 1 in central shell
N 3- Electrons 2 in central shell, 5 in outer
Hmm, ok so need to balance the half equation first, this is a redox reaction.
Hmm, so it's going to be something like
H2 + N2O5 → NH + O3
Step 1. Write down the unbalanced equation ('skeleton equation') of the chemical reaction. All reactants and products must be known. For a better result write the reaction in ionic form.
H2 + N2O5 → NH + O3
Step 2. Separate the process into half reactions. A redox reaction is nothing but both oxidation and reduction reactions taking place simultaneously.
a) Assign oxidation numbers for each atom in the equation. Oxidation number (also called oxidation state) is a measure of the degree of oxidation of an atom in a substance (see: Rules for assigning oxidation numbers).
H02 + N+52O-25 → N-1H+1 + O03
b) Identify and write out all redox couples in reaction. Identify which reactants are being oxidized (the oxidation number increases when it reacts) and which are being reduced (the oxidation number goes down). Write down the transfer of electrons. Carefully, insert coefficients, if necessary, to make the numbers of oxidized and reduced atoms equal on the two sides of each redox couples.
When one member of the redox couple is oxygen with an oxidation state of -2 or hydrogen with an oxidation state of +1, it is best to replace it with a water molecule.
O:3H+12O-2 → O03 + 6e-(O)
H02 → H+12O-2 + 2e-(H)
R:N+52O-25 + 12e- → 2N-1H+1(N)
c) Combine these redox couples into two half-reactions: one for the oxidation, and one for the reduction (see: Divide the redox reaction into two half-reactions).
O:3H+12O-2 + H02 → O03 + H+12O-2 + 8e-
R:N+52O-25 + 12e- → 2N-1H+1
Step 3. Balance the atoms in each half reaction. A chemical equation must have the same number of atoms of each element on both sides of the equation. Add appropriate coefficients (stoichiometric coefficients) in front of the chemical formulas to balance the number of atoms. Never change any formulas.
a) Balance all other atoms except hydrogen and oxygen. We can use any of the species that appear in the skeleton equations for this purpose. Keep in mind that reactants should be added only to the left side of the equation and products to the right.
O:3H+12O-2 + H02 → O03 + H+12O-2 + 8e-
R:N+52O-25 + 12e- → 2N-1H+1
b) Balance the charge. For reactions in an acidic solution, balance the charge so that both sides have the same total charge by adding a H+ ion to the side deficient in positive charge.
O:3H+12O-2 + H02 → O03 + H+12O-2 + 8e- + 8H+
R:N+52O-25 + 12e- + 12H+ → 2N-1H+1
c) Balance the oxygen atoms. Check if there are the same numbers of oxygen atoms on the left and right side, if they aren't equilibrate these atoms by adding water molecules.
O:3H+12O-2 + H02 + H2O → O03 + H+12O-2 + 8e- + 8H+
R:N+52O-25 + 12e- + 12H+ → 2N-1H+1 + 5H2O
Balanced half-reactions are well tabulated in handbooks and on the web in a 'Tables of standard electrode potentials'. These tables, by convention, contain the half-cell potentials for reduction. To make the oxidation reaction, simply reverse the reduction reaction and change the sign on the E1/2 value.
Step 4. Make electron gain equivalent to electron lost. The electrons lost in the oxidation half-reaction must be equal the electrons gained in the reduction half-reaction. To make the two equal, multiply the coefficients of all species by integers producing the lowest common multiple between the half-reactions.
O:3H+12O-2 + H02 + H2O → O03 + H+12O-2 + 8e- + 8H+| *3
R:N+52O-25 + 12e- + 12H+ → 2N-1H+1 + 5H2O| *2
O:9H+12O-2 + 3H02 + 3H2O → 3O03 + 3H+12O-2 + 24e- + 24H+
R:2N+52O-25 + 24e- + 24H+ → 4N-1H+1 + 10H2O
Step 5. Add the half-reactions together. The two half-reactions can be combined just like two algebraic equations, with the arrow serving as the equals sign. Recombine the two half-reactions by adding all the reactants together on one side and all of the products together on the other side.
9H+12O-2 + 2N+52O-25 + 3H02 + 24e- + 3H2O + 24H+ → 3O03 + 4N-1H+1 + 13H2O + 24e- + 24H+
Step 6. Simplify the equation. The same species on opposite sides of the arrow can be canceled. Write the equation so that the coefficients are the smallest set of integers possible.
2N+52O-25 + 3H02 → 3O03 + 4N-1H+1 + H2O
Calculating pH
DETERMINE THE PH OF EACH SOLUTION
» [H] = 1 x 10-9M
pH =
» POH = 3
pH =
» [OH ) = 1 x 10-2 M
pH =
» POH = 7
pH =
Answer:
The answer to your question is given below
Explanation:
1. Data obtained from the question include:
Hydrogen ion concentration, [H+] = 1x10^-9M
pH =..?
pH = - log [H+]
pH = - log 1x10^-9
pH = 9
2. Data obtained from the question include:
pOH = 3
pH =.?
Recall:
pH + pOH = 14
pH + 3 = 14
Collect like terms
pH = 14 - 3
pH = 11
3. Data obtained from the question include:
Hydroxide ion concentration, [OH-] = 1x10^-2M
pH =..?
First, we shall determine the pOH. This is illustrated below
pOH = - Log [OH-]
pOH = - Log 1x10^-2
pOH = 2
Finally, we can obtain the pH as follow:
pH + pOH = 14
pOH = 2
pH + 2 = 14
Collect like terms
pH = 14 - 2
pH = 12
4. Data obtained from the question include:
pOH = 7
pH =.?
Recall:
pH + pOH = 14
pH + 7 = 14
Collect like terms
pH = 14 - 7
pH = 7
is Naci a metal or none metel
Answer:
Salt (NaCl) is an ionic bond that consists of Sodium (Na) which is a metal with positive charge combines with Chlorine (Cl), a nonmetal with a negative charge.
Explanation:
Which structural formula represents an isomer?
Answer: 4
Explanation: same amt of Hs Cs and Cls
The Option 4 has same number of atoms but arranged differently so it is the isomer of the given compound.
What is an Isomer ?Isomers are compounds that contain exactly the same number of atoms, i.e., they have exactly the same empirical formula, but differ from each other by the way in which the atoms are arranged.
By the definition of Isomer we can understand that we have to look for a compound that has same number of Carbon , Hydrogen and Chlorine atoms as that given .
Number of Carbon atoms = 3
Number of Hydrogen atoms = 6
Number of Chlorine atoms = 2
It can be seen that there are same number of Carbon , Hydrogen and Chlorine atoms in the fourth option , so Option 4 is the correct answer.
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Please help me out on this question!!
Answer:
Water H2O
Explanation:
A solvent is defined as being able to dissolve other substances, the fertilizer is being dissolved in the water prior to watering the plants, therefore the water is the solvent in this case.
A student dissolves 1 g of sugar in 10 g of water she then determines the mass of the solution what is the mass of dissolved sugar and water
Answer:
11grams
Explanation:
Use the law '' conversation of mass ''
Because the sugar dissolved in water.
Cheers! :D
PS: Mark me as brianest. Thx.
A student is trying to dissolve 20 grams of sugar in a beaker containing 250 milliliters of water at room temperature. What can the student do to make the sugar dissolve faster in the water? a. decrease the temperature of the water b.use larger pieces c.stir rapidly d.use less water
Answer:
C. Stir rapidly
Latent heat of vaporization is used to (1 Point) (a) overcome the forces of attraction between molecules in solid-state. (b) increase the kinetic energy of molecules in a liquid state. (c) overcome the forces of attraction between molecules in a liquid state. (d) increase the kinetic energy of molecules in the vapour state.
Answer:
Not sure what the answer is
Explanation:
I did this a while ago and dont remember sorry
mixture of 75 cm3of oxygen and 12.5 cm3 of a gaseous hydrocarbon H were exploded in an eudiometer. After cooling to room temperature, 50 cm3 of gas was left and when this was shaken with KOH solution, 12.5 cm3 of oxygen remained. Given that all the volumes were measured at same temperature and pressure, calculate the molar mass of the hydrocarbon H.
Answer:
molar mass of C₃H ₈ = 44 g/mole
Explanation:
Computation of the amount of oxygen that reacts .
⇒ 75 - 12.5
⇒ 62.5 cm³
Computation of proportion of hydrocarbons
2 mole hydrocarbons 3n+1 oxygen
⇒ 3 n + 1 = [62.5 × 2] / 12.5
⇒ 3 n + 1 = 10
⇒ n = 3
So,
Formula of the hydrocarbon is C₃H ₈
Computation of molar mass of C₃H ₈
⇒ [12×3] + [1×8]
⇒ 44 g/mole
What is the potential energy of the bowling ball as it sits on top of a building?
Answer:
Potential energy is the amount of energy calculated from an object's height off the ground.
Explanation:
Potential energy = Mass x Height x Gravity
What determines the average kinetic energy of the particles in a gas?
A.
the number of collisions
B.
the number of particles
OC.
the size of the particles
D.
the temperature
Answer:
D
The temperature.
Explanation:
Which equation represents neutralization?
6Li(s) + N2(g) → 2Li3N(S)
2Mg(s) + O2(g) → 2MgO(S)
2KOH(aq) + H2SO4(aq) → K2SO4(aq) + 2H2O(l)
Pb(NO3)2(aq) + K2CrO4(aq) → 2KNO3(aq) PbCrO4(s)
Answer:
2KOH(aq) + H2SO4(aq) → K2SO4(aq) + 2H2O(l)
Explanation:
A neutralization reaction refers to any reaction between an acid and a base to form salt and water only. In a neutralization reaction, the key reaction that takes place to produce water is shown ionically below;
H^+(aq) +OH^-(aq) ----> H2O(l)
Looking at all the options provided, our gaze will have to settle on the reaction;
2KOH(aq) + H2SO4(aq) → K2SO4(aq) + 2H2O(l)
We can clearly see that there is an acid that reacts with a base to form a salt and water. The base contains the OH^- ion while the acid contains the hydrogen ion.
This is the only reaction of this sort among the options hence it is the correct answer.
The best method to improve air quality is to
A. use technology to reduce the pollutants in air
b. produce less pollution
c. produce less pollution and use technology to reduce the pollutants in air
d. better utilize land and technology to prevent pollution
Please select the best answer from the choices provided
Answer:
A produce less polution
Explanation:
Answer:
C) produce less pollution and use technology to reduce the pollutants in air
Explanation:
EDG2020
What's the sequence of a single complete engine cycle?
Intake, compression, power, exhaust
Intake, power, compression, exhaust
Compression, power, intake, exhaust
Intake, exhaust, compression, power
Answer:
Intake, compression, power, and exhaust
Explanation:
A four-stroke cycle engine is an internal combustion engine that utilizes four distinct piston strokes (intake, compression, power, and exhaust) to complete one operating cycle. The piston make two complete passes in the cylinder to complete one operating cycle.
The sequence of a single complete engine cycle is Intake, compression, power, exhaust. Therefore option 1 is correct.
1. Intake: In this step, the intake valve opens, allowing a mixture of air and fuel to enter the combustion chamber.
2. Compression: After the intake stroke, the intake valve closes, and the piston moves back up, compressing the air-fuel mixture. This compression increases the pressure and temperature inside the cylinder, preparing it for combustion.
3. Power: Once the air-fuel mixture is compressed, the spark plug ignites it. The burning mixture rapidly expands, generating a high-pressure force that pushes the piston down.
4. Exhaust: After the power stroke, the exhaust valve opens, and the piston moves back up, pushing the burned gases out of the cylinder and into the exhaust system.
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I’ve gotten the answer as x=.478 but when plugging back in, .46/.478 ≠ .22. Help please
Answer:
15. 2.66 moles .
16. 2.09L.
Explanation:
Molarity of a solution is simply defined as the mole of solute per unit litre of the solvent. Mathematically, it is represented as:
Molarity = mole /Volume.
With the above formula, let us answer the questions given above
15. Data obtained from the question include the following:
Volume of solution = 1.4L
Molarity = 1.9M
Mole of solute =.?
Molarity = mole /Volume
1.9 = mole / 1.4
Cross multiply
Mole = 1.9 x 1.4
Mole = 2.66 moles
Therefore, the mole of the solute present in the solution is 2.66 moles.
16. Data obtained from the question include the following:
Mole of solute = 0.46 mole
Molarity = 0.22M
Volume of solvent (water) =.?
Molarity = mole /Volume
0.22 = 0.46/Volume
Cross multiply
0.22 x Volume = 0.46
Divide both side 0.22
Volume = 0.46/0.22
Volume = 2.09L
Therefore, 2.09L of water is required.
Carbon-14 is a common isotope of the element. How many electrons
does it contain?
O 14
O 12
O 8
O 6
1. How many acetate ions are in the compound strontium acetate?
Answer: 2 Acetate ions
Explanation:
Strontium Acetate, has the molecular formular to be; C4H6O4Sr ( or in a linear form, Sr(CH3COO)2), contains two acetate ions.
In one molecule of strontium acetate (Sr(CH₃COO)₂), there are two acetate ions (CH₃COO⁻).
We must first comprehend the chemical composition of strontium acetate in order to calculate the quantity of acetate ions present.
Acetate ions (CH₃COO⁻) and strontium ions (Sr²⁺) combine to linear form the ionic compound strontium acetate. Sr(CH₃COO)₂ is the chemical formula for strontium acetate.
(CH₃COO)₂ stands for two acetate ions in the formula. The (CH₃COO⁻) ion, also referred to as the acetate ion, is a polyatomic ion made up of two carbon (C), three hydrogen (H), and two oxygen (O) atoms. It has a -1 charge overall.
Thus, there are two acetate ions (CH₃COO⁻) in a single molecule of strontium acetate (Sr(CH₃COO)₂).
It's crucial to understand that in ionic compounds like strontium acetate, the ratio of positively charged ions (cations) to negatively charged ions (anions) must be balanced in order to produce a neutral compound. In this instance, the two -1 charges of the acetate ions (CH₃COO⁻) counterbalance the two +2 charges of the strontium ions (Sr²⁺), creating a neutral molecule.
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Which gas relights a glowing splint? *
C hydrogen
A ammonia
B carbon dioxide
D oxygen
Answer:
Oxygen
Explanation:
A glowing splint applied to a sample of gas "oxygen" will relight.
if an experiment produces 5g but should have made 500 g what is the percent yield
how many moles of H2O will be produced from 6 moles of 02
Answer: 12 moles H20
Explanation:
The tools of choice for stoichiometry problems will always be the mole ratios that exist between the chemical species that take part in the reaction.
2H2 [g] + O2 [g]------> 2H 2O (1]]
In a laboratory, Carlos places one plate with grape jelly and another plate with cooked brown rice inside an ant farm. The next day, he finds that both plates are filled with ants. Carlos wonders if there are certain household foods that are more effective than others at attracting ants. How could Carlos use the scientific inquiry process to determine which foods are most effective at attracting ants? Check all that apply.
Answer:
The Answers are: A. C. D.
Answer:
by making quantitative observations about the number of ants found on each plate of food
by comparing a plate of cooked brown rice to another household food such as peanut butter
by designing an experiment to test different foods and the number of ants each food attracts
Explanation:
It was right on edge
2 Points
You are a forensic scientist working for a police department. One piece
of evidence from your current case is a letter written in a strange ink. You
must separate the pigments in the ink to determine what it is made from.
What procedure should you use?
A. Distillation
O
B. Evaporation
C. Filtering
d
d
D. Chromatography
Reset Selection
What are the following equations for each:
1. Ratio of product concentrations reactant concentrations at equilibrium.
2. Ratio of partial pressures of products to partial pressures of reactants (for gas phase reactions only) at equilibrium
3. Ratio of products reactants for the reaction of a weak base with water at equilibrium.
4. The thermodynamic equilibrium constant, calculated from thermodynamic data, not concentrations.
5. The autoionization constant for water (= 1.0 x 10-14).
6. Ratio of products reactants for the reaction of a weak acid with water at equilibrium
Answer: thats alot of reading
Explanation:
Which of following is the most accurate description of a piston in an internal-
combustion engine?
A shaft that converts the up-and-down motion into a rotary motion
A plug that protrudes through the cylinder head and makes sparks that ignite the
air-and-fuel mixture
A can-shaped component that moves smoothly up and down and is the main
moving part
O A hollow metal tube drilled into the solid metal engine block
Answer:
A can-shaped component that moves smoothly up and down and is the main moving part
Explanation:
I chose the other answer that other person listed but got it wrong. This instead is the correct answer
Answer:
C. A can-shaped component that moves smoothly up and down and is the main
moving part
Explanation:
The piston is a can-shaped component that can move smoothly up and down inside the cylinder; it moves up to compress the air-and-fuel mixture and is pushed down when the spark plug ignites the mixture, which causes an explosion.
