Answer:
They are made up of electrons, neutrons and protons
Explanation:
28. Element X is powerful enough to reduce sodium ions to sodium metal. Barium is a strong enough reducing agent to reduce X +to X. What is the identity of element X? _____________
Answer:
hope it's correct.
Explanation:
element is nickel.
What forces cause mechanical weathering? Choose more than one
answer.
Answer:
mineral crystal growth
acid rain
carbonic acid
Answer:
Mineral crystal growth, Acid rain, Carbonic acid
Write a balanced half-reaction for the oxidation of gaseous nitric oxide (NO) to aqueous nitrous acid (HNO2) in acidic aqueous solution.
Answer:
NO + H₂O → HNO₂ + 1 e- + 1 H⁺
Step-by-step explanation:
NO ⇒ oxidation number of N = +2
HNO₂ ⇒ oxidation number of N= +3
Therefore, NO has to lose 1 electron to be oxidized to HNO₂. We write the half-reaction with 1 electron (1 e-) in the products side.
NO → HNO₂ + 1 e-
Now, we have 0 electrical charges in the reactants side, and a total of -1 electrical charge in the products side. As the reaction is in acidic aqueous solution, we have to add H⁺ ions to balance the charges. We perform the balance by adding 1 H⁺ (positive charge) to neutralize the negative charge in the side of the products:
NO → HNO₂ + 1 e- + 1 H⁺
Now, we perform the mass balance. We have:
N: 1 atom in both sides
O: 1 atom in reactants side and 2 atoms in products side
H: 0 atoms in reactants side, 2 atoms in products side.
Thus, we have to add 1 H₂O molecule to the reactants side to equal the masses:
NO + H₂O → HNO₂ + 1 e- + 1 H⁺
Finally, the oxidation half-reaction is:
NO + H₂O → HNO₂ + 1 e- + 1 H⁺
K2CrO4 + Ba(NO3)2 = BaCrO4 +2 KNO3
If 5.0 grams of K2CrO4 are put into a reaction, how many grams of BaCrO4 will be produced
Which statement describes a major drawback of the Bohr model that caused scientists to replace it?
(A) It worked only for helium and larger atoms.
(B) It did not identify the distance between an electron and the nucleus.
(C) It contradicted the Heisenberg uncertainty principle.
(D) It stated that spectral lines of atoms are similar.
on edgen
Answer:
C.it contradicted the heinsberg uncertainly principle
Answer:
C.it contradicted the heinsberg uncertainly principle
Explanation:
12oz of water initially at 75oF is mixed with 20oz of water intiially at 140oF. What is the final temperature?
Answer:
[tex]115.625^{\circ}\text{F}[/tex]
Explanation:
[tex]m_1[/tex] = First mass of water = 12 oz
[tex]m_2[/tex] = Second mass of water = 20 oz
[tex]\Delta T_1[/tex] = Temperature difference of the solution with respect to the first mass of water = [tex](T-75)^{\circ}\text{F}[/tex]
[tex]\Delta T_2[/tex] = Temperature difference of the solution with respect to the second mass of water = [tex](T-75)^{\circ}\text{F}[/tex]
c = Specific heat of water
As heat gain and loss in the system is equal we have
[tex]m_1c\Delta T_1=m_2c\Delta T_2\\\Rightarrow m_1\Delta T_1=m_2\Delta T_2\\\Rightarrow 12(T-75)=20(140-T)\\\Rightarrow 12T-900=2800-20T\\\Rightarrow 12T+20T=2800+900\\\Rightarrow 32T=3700\\\Rightarrow T=\dfrac{3700}{32}\\\Rightarrow T=115.625^{\circ}\text{F}[/tex]
The final temperature of the solution is [tex]115.625^{\circ}\text{F}[/tex].
A 45.0 mL solution of 0.0450 M hydroxylamine is extracted with 125 mL of solvent. The distribution constant for the reaction is 5.00 and the pKa of the protonated form of hydroxylamine is 5.960. Calculate the concentration of hydroxylamine remaining in the aqueous phase at pH=4.50 and pH=6.50 .
Answer:
pH = 4.5, concentration = 0.045 M.
pH = 6.5, concentration = 0.175 M.
Explanation:
The ka for the can be calculated by using the formula below;
Ka = 10^-pka = 10^-5.960 = 1.1 × 10^-6
The concentration of hydrogen ion at pH = 4.50 can be calculated as given below;
{H^+ } = 10^-4.50 = 3.2 × 10^-5 M.
(NB=> 10 in this regards means the inverse of log).
The next step is to determine the distribution coefficient which can be calculated by using the formula below;
distribution coefficient = (partition coefficient) × ka / ka + ( concentration of Hydrogen ion,H^+).
distribution coefficient =( 5 × 1.1 × 10^-6 ) / 1.1 × 10^-6 + 3.2 × 10^-5 M. = 5.5 × 10^-6/ 3.2 = 0.00000171875
The fraction remaining from the compound = 45.0 mL / 45.0 mL + (0.00000171875 × 125).
= 0.999995.
Thus, the concentration at pH = 4.5 = 0.999995 × 0.0450 M = 0.045 M
(B). pH=6.50, thus the concentration of Hydrogen ion = 10^-6.5 = 3.2 × 10^-7 M.
distribution coefficient = (partition coefficient) × ka / ka + ( concentration of Hydrogen ion,H^+).
distribution coefficient = (5 × 1.1 × 10^-6)/ 1.1 × 10^-6 + 3.2 × 10^-7 M).
distribution coefficient = 5.5 × 10^-6/ 1.42 × 10^-6 = 3.9.
Therefore, the concentration = 3.9 × 0.0450 M = 0.175 M.
Which of these is NOT evidence that a chemical change has taken place?
temperature rising when 2 substances are mixed
gas production
color change
melting
Write the molecular, ionic, and net ionic equations for the reaction of Sr(NO3)2(aq) and Li2SO4(aq).
Answer:
Molecular: [tex]Sr(NO_3)_2(aq) +Li_2SO_4(aq)\rightarrow SrSO_4(s)+2LiNO_3(aq)[/tex]
Ionic: [tex]Sr^{2+}(aq)+2NO_3^-(aq) +2Li^{2+}(aq)+SO_4(aq)^{2-}\rightarrow SrSO_4(s)+2Li^+(aq)+2NO_3^-(aq)[/tex]Net ionic: [tex]Sr^{2}(aq)+SO_4(aq)^{2-}\rightarrow SrSO_4(s)[/tex]
Explanation:
Hello!
In this case, since the molecular, ionic and net ionic equations show the complete molecules, ions and resulting ions respectively, for the reaction between strontium nitrate and lithium sulfate, we can notice the formation of solid strontium sulfate and lithium nitrate as shown below:
[tex]Sr(NO_3)_2(aq) +Li_2SO_4(aq)\rightarrow SrSO_4(s)+2LiNO_3(aq)[/tex]
Which is the molecular equation showing both reactants and products as molecules. Then, the ionic equation shows all the reactants and products as ions, considering that aqueous solutions dissociate whereas solid, liquid and gaseous molecules do not, therefore, we obtain:
[tex]Sr^{2+}(aq)+2NO_3^-(aq) +2Li^{2+}(aq)+SO_4(aq)^{2-}\rightarrow SrSO_4(s)+2Li^+(aq)+2NO_3^-(aq)[/tex]
Finally, for the net ionic equation, we cancel out the spectator ions, which are those at both reactants and products:
[tex]Sr^{2+}(aq)+SO_4(aq)^{2-}\rightarrow SrSO_4(s)[/tex]
Best regards!
A further explanation is below.
Given:
[tex]Sr(NO_3)_2 (aq)[/tex] (Strontium nitrate)[tex]L1_2SO_4 (aq)[/tex] (Lithium sulfate)Strontium nitrate reacts with Lithium sulfate just to produce Strontium sulfate ([tex]Sr(NO_3)_2[/tex]) and Lithium nitrate ([tex]Li NO_3[/tex]).
The molecular equation will be:
→ [tex]Sr(NO_3)_2(aq) +Li_2SO_4(aq) \rightarrow SrSO_4 (s) +2LiNO_3 (aq)[/tex]
The complete ionic equation will be:
→ [tex]Sr^{2+} (aq) +2NO_3^- (aq) +2Li^+ (aq)+ SO_4^{2-} (aq) \rightarrow SrSO_4 (s)+2Li^+ (aq) +2NO_3^- (aq)[/tex]
By removing the uncharged ions from equation's will be:
Spectator ion:
→ [tex]2Li^+ (aq), 2NO_3^- (aq)[/tex]
Net ionic equation will be:
→ [tex]Sr^{2+}(aq)+SO_4^{2-} (aq) \rightarrow SrSO_4 (s)[/tex]
Thus the response above is right.
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Where do karst regions occur?
Answer:
Image result for Where do karst regions occur?
Karsts are found in widely scattered sections of the world, including the Causses of France; the Kwangsi area of China; the Yucatán Peninsula; and the Middle West, Kentucky, and Florida in the United States.
Explanation:
Answer:
Middle West Kentucky.
Explanation:
Karst are found in widely scatter sections of the world.
What volume will be occupied by 33.0 grams of CO2 at 500 torr and 27 °C?
Answer:
V = 27.98 L
Explanation:
Given data:
Mass of CO₂ = 33.0 g
Pressure = 500 torr
Temperature = 27°C
Volume occupied = ?
Solution:
Number of moles of CO₂:
Number of moles = mass/molar mass
Number of moles = 33.0 g/ 44 g/mol
Number of moles = 0.75 mol
Volume of CO₂:
PV = nRT
R = general gas constant = 0.0821 atm.L/ mol.K
Now we will convert the temperature.
27+273 = 300 K
Pressure = 500 /760 = 0.66 atm
By putting values,
0.66 atm×V = 0.75 mol × 0.0821 atm.L/ mol.K × 300 K
V = 18.47 atm.L/0.66 atm
V = 27.98 L
The volume that will be occupied by 33.0 grams of CO2 at 500 torr and 27 °C is 28.11L.
IDEAL GAS LAW:The volume of an ideal gas can be calculated using the ideal gas law equation as follows:
PV = nRT
Where;
P = pressure (atm)V = volume (L)n = number of moles (mol)R = gas law constant (0.0821 Latm/molK)T = temperature (K)According to this question;
P = 500torr = 0.657atmV = ?n = 33/44 = 0.75molT = 27°C = 27 + 273 = 300K0.657 × V = 0.75 × 0.0821 × 300
0.657V = 18.4725
V = 18.4725 ÷ 0.657
V = 28.11L
Therefore, the volume that will be occupied by 33.0 grams of CO2 at 500 torr and 27 °C is 28.11L.
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A. 1
B. 2
C. 3
D. 4
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Suppose there is a gaseous mixture of nitrogen and oxygen. If the total pressure of the mixture is 480 mmHg, and the partial pressure of nitrogen is 290 mmHg, calculate the partial pressure of oxygen in the mixture using Dalton's law.
Answer:
Partial pressure of oxygen = 190 mmHg
Explanation:
From the question;
Mixture contains only nitrogen and oxygen
Total pressure of the mixture = 480 mmHg
Partial pressure of nitrogen = 290 mmHg
Dalton's law states that the pressure of a system is as a result of the sum of the partial pressures of the individual components of the mixture. This means that in this mixture;
Pressure of mixture = Partial Pressure of Nitrogen + Partial Pressure of Oxygen
480 = 290 + Partial pressure of oxygen
Partial pressure of oxygen = 480 - 290
Partial pressure of oxygen = 190 mmHg
A mixture of 10.0 g of Ne and 10.0 g Ar have a total pressure of 1.60 atm. What is the partial pressure of Ar
Answer:
0.53 atm
Explanation:
First we have to obtain the number of moles of each gas.
Number of moles of Ne = 10g/20g/mol = 0.5 moles
Number of moles of Ar = 10 g/40 g/mol = 0.25 moles
Total number of moles = 0.5 moles + 0.25 moles = 0.75 moles
Partial pressure of Ar = number of moles of Ar/Total number of moles * total pressure
Partial pressure of Ar = 0.25 moles/ 0.75 moles * 1.60 atm
Partial pressure of Ar = 0.53 atm
5. To keep your lunch cold at the beach, would you want a material
that minimizes heat transfer or maximizes heat transfer? Explain (keep it short please)
Answer:
Minimizes heat transfer
Explanation:
To keep my lunch from getting cold at the beach, a material the minimizes heat transfer will be the most desirable.
Such material should be modified to prevent had transfer by convection, conduction and radiation. This kind of material is desirable because heat generally flows from a place of high amount to that of low amount. Since the food will mostly have a temperature higher than the ambient one, it is expected that heat will flow away from the food to the environment. This will make the food cold. If such heat transfer is prevented, then, the food will remain hot.9. What type of bond is pictured in the image below?
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Alt
--
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Alt
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Alth
AN
1
a. covalent bond
b. ionic bond
c. metallic bond
d. electron bond
Answer:
metallic bond
because this diagram is electron gas theory which shows metallic bond
write the chemical formula of tetraphosporus osctasulfide
Answer:
P4S8 .
the chemical formula of Tetraphosporus osctasulfide is p4S8
Which of the following statements correctly describes the function of cell parts?
A. The cell membrane determines which type of cell will develop.
B. The nucleus contains all the nutrients that the cell needs.
C. The mitochondria are the power plants of the cell.
D. The genes contain hemoglobin.
The statements correctly describes the function of cell parts is the mitochondria are the power plants of the cell. Therefore, option C is correct.
What do you mean by the mitochondria ?The cytoplasm of a cell contains tiny structures (fluid that surrounds the cell nucleus). The majority of a cell's energy is produced by mitochondria, which also have unique genetic material distinct from that present in the nucleus.
Oxidative phosphorylation, which produces ATP using the energy generated during the oxidation of the food we ingest, is the traditional function of mitochondria.
For the majority of biochemical and physiological activities, including growth, mobility, and equilibrium, ATP is used as the main energy source in turn.
Thus, option C is correct.
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List any three quantum numbers that describe an electron in an atom and state the relationship between any of the two
Explanation:
To completely describe an electron in an atom, four quantum numbers are needed: energy (n), angular momentum (ℓ), magnetic moment (mℓ), and spin (ms).
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After an afternoon party, a small cooler full of ice is dumped onto the hot ground and melts. If the cooler contained 6.60 kg of ice and the temperature of the ground was 42.5 °C, calculate the energy that is required to melt all the ice at 0 °C. The heat of fusion for water is 80.0 cal/g.
Answer:
The quantity of heat required to melt all the ice at 0°C is 2.21 * 10⁶ J
Explanation:
Latent heat of fusion is the heat absorbed by a unit mass of a given solid at its melting point that completely converts the solid to a liquid at the same temperature. Its unit is Joules/kg or Joules/g.
1 calorie = 4.184 Joules
Therefore , 80.0 cal/g = 80.0 cal/g * 4.184 J/cal = 334.72 J/g
1 g = 0.001 kg; Heat of fusion in J/kg = 334.72 J/g * 1g /0.001 kg = 3.35 * 10⁵ J/kg
Quantity of heat, Q = mass * latent heat of fusion of ice
quantity of heat required = 6.60 kg * 3.35 * 10⁵ J/kg
Quantity of heat required = 2.21 * 10⁶ J
Therefore, the quantity of heat required to melt all the ice at 0°C is 2.21 * 10⁶ J
The chart shows the frequencies of certain colors of visible light. A 2 column table with 4 rows. The first column is labeled light with entries red, violet, green, orange. The second column is labeled frequency in hertz with entries 4.5 times 10 Superscript 14 baseline, 7.5 times 10 Superscript 14 baseline, 6.0 times 10 Superscript 14 baseline, 5.0 times 10 Superscript 14 baseline. Which colors will eject electrons when they strike sodium, which has a frequency threshold of 5.7 × 1014 Hz? violet and green red and orange violet only red, violet, green, and orange
Answer:
Violet only
Explination:
Violet is the only color that will eject electrons when it strikes sodium.
The colors that will eject electrons when there's a strike with sodium from the chart will be A. Violet and green.
ElectronsFrom the complete information, William made a chart in order to illustrate the result of the experiment that was made with the photoelectric effect.
In this case, the colors that will eject electrons when they strike sodium, with the frequency threshold will be violet and green.
This was gotten from the result that the frequencies of light were lower than the frequency threshold.
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Use Coulomb's Law to explain why and how atomic radius and IE have an inverse relationship.
Answer:
Such a relationship between atomic number and atomic radius is a direct correlation. an inverse correlation. According to Coulomb's Law, as the atomic number increases within a series of atoms, the nuclear attraction for electrons will also increase, thus pulling the electron(s) closer to the nucleus.
Explanation:
The compound F20 has two lone pairs on the central oxygen atom. What's the structure of an F2O molecule? Is this compound polar or non-polar?
A. Trigonal planar, polar
B. Bent or angular non-polar
C. Bent or angular polar
D. Trigonal planar non-polar
Answer:
Bent or Angular, Polar
Explanation:
I just took the test!
Answer:
C. Bent or angular polar
Explanation:
What is pure convalent bond
Answer:
Pure covalent bonds exist between two atoms with the same electronegativities. A pure covalent bond has no ionic character at all. Diatomic elements are good examples of pure covalent bonds where the electrons are evenly shared between both nuclei.
Explanation:
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Demonstrate how you can prepare 250ml 0.25M hydrogen peroxide from a solution of 20g/100ml of hydrogen peroxide.
To prepare 250 ml 0.25 M hydrogen peroxide, 10.63 ml of 20g/100 ml hydrogen peroxide has been taken and made up the volume to 250 ml.
The dilution of the sample can be prepared with the help of expression:
M1V1 = M2V2
M1 = molarity of the concentrated solution
V1 = volume of concentrated solution
M2 = molarity of diluted solution
V2 = volume of diluted solution.
The molarity of concentrated solution has been:
Molarity = [tex]\rm \dfrac{weight}{molecular\;weight}\;\times\;\dfrac{1000}{Volume\;(ml)}[/tex]
The 20g/100 ml Hydrogen peroxide has molarity:
Molarity = [tex]\rm \dfrac{20}{34.0147}\;\times\;\dfrac{1000}{100}[/tex]
Molarity of Hydrogen peroxide = 5.879 M
The volume of 5.879 M hydrogen peroxide is required to prepare 0.25 M hydrogen peroxide has been:
Volume of Hydrogen peroxide (20g/100 ml) [tex]\times[/tex] 5.879 = 250 ml [tex]\times[/tex] 0.25 M
Volume of Hydrogen peroxide (20g/100 ml) = 10.63 ml.
To prepare 250 ml 0.25 M hydrogen peroxide, 10.63 ml of 20g/100 ml hydrogen peroxide has been taken and made up the volume to 250 ml.
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How many milliliters of 6.2 M M HCl H C l solution are needed to obtain 0.18 mol m o l of HCl H C l ?
Answer:
29 mL HCl
General Formulas and Concepts:
Chem
Molarity = moles of solute / liters of solutionExplanation:
Step 1: Define
6.2 M HCl
0.18 mol HCl
x L mol HCl
Step 2: Define conversions
1 L = 1000 mL
Step 3: Find L
6.2 M HCl = 0.18 mol HCl / x L HCl
(x L HCl)(6.2 M HCl) = 0.18 mol HCl
x L HCl = 0.18 mol HCl / 6.2 M HCl
x = 0.029032 L HCl
Step 4: Convert
[tex]0.029032 \ L \ HCl(\frac{1000 \ mL \ HCl}{1 \ L \ HCl} )[/tex] = 29.0323 mL HCl
Step 5: Check
We are given 2 sig figs. Follow sig fig rules.
29.0323 mL HCl ≈ 29 mL HCl
Answer:
29 mL HCl
Explanation:
A hutch weighs 150 lbs and it’s base has a length and width of 15 in and 34 in, respectively. What is the pressure exerted by the hutch on the floor?
Answer:0.29
Explanation:
To determine the pressure of the hutch on the floor, we must first calculate the area of the base of the hutch.
A=lw=(15in.)(34in.)=510in.2
We can now use the formula to calculate pressure.
P=FAP=150lbs510in.2P≈0.294lbin.2
Rounding to two significant figures, the pressure exerted by the hutch on the floor is 0.29lbin.2.
do seeds need energy to germinate
Answer:
Seeds need oxygen so that they can produce energy for germination and growth. The embryo gets energy by breaking down its food stores. Like all organisms, this is done through a process known as aerobic respiration. —a series of reactions where energy is released from glucose, using oxygen.
Which is the best example and explanation that a physical change has occurred?
fireworks exploding, because energy is released as light and heat
gasoline burning, because it forms water vapor and carbon dioxide
O crushing an ice cube, because the chemical structure of the ice cube is changed
dicing potatoes, because the molecules are separated but remain the same substance
dicing potatoes, because the molecules are separated but remain the same substance
Answer:
For the people wondering, yes, dicing potatoes is the correct answer. Because a new substance has not formed.
Plz what’s the answer to this
Answer: E
Explanation:hope this helps you out