Answer: The electronic configuration of selenium is [tex]1s^22s^22p^63s^23p^64s^23d^{10}4p^4[/tex]
Explanation:
The atomic number is defined as the number of protons or number of electrons present in a neutral atom.
Number of electrons will be equal to the atomic number of an atom.
Electronic configuration is defined as the representation of electrons in an atom.
Selenium is the 34th element of the periodic table.
The electronic configuration of Selenium is [tex]1s^22s^22p^63s^23p^64s^23d^{10}4p^4[/tex]
It has 6 electrons that are present in the outermost shell.
Write the balanced chemical equation when carbonate ores are heated in a limited supply of air.
Answer:
MCO₃ (s) -> MO (s) + CO₂ (g)
Explanation:
M = a metal
This process is called calcination and is generally used to remove impurities. It's most common use is to remove carbon from limestone.
CaCO₃ (s) -> CaO (s) + CO₂ (g)
An iron block of mass 18 kg is heated from 285 K to 318 K. If 267.3 kJ is required, what is the specific heat of iron?
A. 490.05
B. 158.77
C. 145.80
D. 450.00
Answer:
D. 450 J/kgK
Explanation:
Using the formula as follows:
Q = m × c × ∆T
Where:
Q = amount of heat absorbed/released (J)
m = mass of substance (g)
c = specific heat capacity
∆T = change in temperature (°C)
According to the information provided in this question:
Q = 267.3 kJ = 267300J
m = 18kg
∆T = 318K - 285K = 33K
c = ?
Q = m × c × ∆T
c = Q ÷ m∆T
c = 267300 ÷ 18 × 33
c = 267300 ÷ 594
c = 450 J/kgK
according to the article, which of the following may be affected by a scientists bias?
write your 5 ways how to you can help earth
Answer:
any 5 ways to prevent earth are:
1.using ( 3R) principles Reduce, reuse, and recycle.
2.Educate yourself
3.Conserve water resources and other natural resources
4.Use long-lasting light bulbs.
5.stop deforestation and start afforestaion
The reaction from NaOH and CH3COOH gives
a. Basic Salt
b. Acidic Salt
c. Normal Salt
d. Neutral Salt
When triglycerides are metabolized, ___ is/are converted to pyruvate or glucose, whereas ____ is/are converted to acetyl CoA.
Answer:
Glycerol;Pyruvate
Explanation:
Metabolism of triglycerides occur through a process known as lipolysis. During triglyceride metabolism, Glycerol is converted to pyruvate or glucose through glycolysis or gluconeogenesis respectively. Glycerol enters these pathways by being converted to glycerol-3-phosphate (reaction catalyzed by glycerol kinase) which can in turn be converted to dihydroxyacetone phosphate (reaction catalyzed by glycerol-3-phosphate dehydrogenase).
NOTE: Dihydroxyacetone phosphate is a compound/substrate found in both glycolysis and gluconeogenesis.
The end product of glycolysis is pyruvate; this pyruvate, under aerobic condition is converted to acetyl coA (reaction catalyzed by pyruvate dehydrogenase complex), an intermediary of the Tricarboxylic acid cycle.
What is the weight on Earth of an apple with mass 150g?
The normal boiling point of ethanol is 78.4 oC. Its enthalpy of vaporization is 38.6 kJ/mol. Estimate the vapor pressure of ethanol at 26.3 oC.
Answer: The vapor pressure of ethanol at [tex]26.3^{o}C[/tex] is 238.3 torr.
Explanation:
Given: [tex]\Delta H_{vap}[/tex] = 38.6 kJ/mol
[tex]T_{1} = 26.3^{o}C = (26.3 + 273) K = 299.3 K[/tex]
[tex]T_{2} = 78.4^{o}C = (78.4 + 273) K = 351.4 K[/tex]
Formula used to calculate the vapor pressure of ethanol is as follows.
[tex]ln\frac{P_{2}}{P_{1}} = \frac{\Delta H_{vap}}{R} [\frac{1}{T_{1}} - \frac{1}{T_{2}}]\\[/tex]
Substitute the values into above formula as follows.
[tex]ln\frac{P_{2}}{P_{1}} = \frac{\Delta H_{vap}}{R} [\frac{1}{T_{1}} - \frac{1}{T_{2}}]\\ \\ln \frac{760 torr}{P_{1}} = \frac{38600 J}{8.314 J/mol K}[\frac{1}{299.3} - \frac{1}{351.4}]\\\frac{760}{P_{1}} = 3.18\\P_{1} = 238.3 torr[/tex]
Thus, we can conclude that the vapor pressure of ethanol at [tex]26.3^{o}C[/tex] is 238.3 torr.
What is the equilibrium constant of pure water at 25°C
Select all that apply Select the correct statements explaining how manometers measure the pressure of a gas in an experiment. Multiple select question.
In an open-end manometer, the gas pressure pushes on the Hg surface on one arm of the U tube and atmospheric pressure gas pushes on the other.
In an closed-end manometer, the gas pressure pushes on the Hg surface on one arm of the U tube and atmospheric pressure gas pushes on the other.
In an open-end manometer, the gas pressure is equal to the difference in column heights in the two arms of a U tube.
In an closed-end manometer, the gas pressure is equal to the difference in column heights in the two arms of a U tube.
The gas pressure is directly related to the height of a column of mercury it produces in a U tube.
Answer:
-In an closed-end manometer, the gas pressure is equal to the difference in column heights in the two arms of a U tube.
-In an open-end manometer, the gas pressure pushes on the Hg surface on one arm of the U tube and atmospheric pressure gas pushes on the other.
-The gas pressure is directly related to the height of a column of mercury it produces in a U tube.
Explanation:
Manometer is simply an instrument used for measuring the pressure that is acting on a column of liquid.
Now they could either be open ended or closed ended manometers.
However the difference between both of them is that;
Closed - end manometer are those used to measure absolute pressure while open end manometer is used to measure the gauge pressure.
From operation of a closed end manometer, the gas pressure is read from the difference in column heights of the two arms of the U tube being used. While in open end thermometer, the gas pressure will push the mercury surface on one arm of the U tube while the atmospheric pressure gas will push on the other arm.
Lastly, the height of a column of mercury in the U-tube is directly related to the gas pressure.
Thus, the correct options are A, D, E
explain the chemical reaction
A chemical reaction is when reactants are converted into another substance (also called products). Their reaction rearranges the constituent atoms of the reactants to give different substances as products.
I hope this helps! Please mark me as brainliest!
Have a wonderful day!
The prosecution offers a lab report prepared by a government chemist who examined a white powdery substance seized from a box at Mary's house. The report indicated that the chemist used standard procedures in the analysis of the white substance, and the chemist prepared the report in the ordinary course of business. The report reflects the chemist's conclusion that the substance contained methamphetamine. Write a few sentences characterizing the report as either testimonial or nontestimonial hearsay.
Answer: The report prepared is a nontestimonial hearsay.
Explanation:
The nontestimonial hearsay can be defined as the expert opinion or statement given casually and not for the purpose of keeping or considering it as record by the government agent or agency. Here the given conclusion provided by the chemical expert is an example of nontestimonial hearsay because it is not the output of experimental and analytical procedures instead it is a casual opinion. Testimonial hearsay include the evidences that are based on detailed and thorough analytic procedures.
Consider the balanced chemical equation . How many moles of H 2O are produced when 1.0 mole of C 2H 6 reacts with excess O 2
Answer:
3.0 mol H₂O
Explanation:
Step 1: Write the balanced combustion equation
C₂H₆ + 3.5 O₂ ⇒ 2 CO₂ + 3 H₂O
Step 2: Establish the appropriate molar ratio
The molar ratio of C₂H₆ to H₂O is 1:3.
Step 3: Calculate the moles of H₂O formed from 1.0 mole of C₂H₆
1.0 mol C₂H₆ × 3 mol H₂O/1 mol C₂H₆ = 3.0 mol H₂O
What are the uses of iron and it's reasons.
Answer:
Uses of iron
It is used to manufacture steel and also used in civil engineering like reinforced concrete, girders etc. Iron is used to make alloy steels like carbon steels with additives such as nickel, chromium, vanadium, tungsten, and manganese.
Answer:
iron is used to make water pipes.
used for making machines in industries.
used for making steam engine.
How many GRAMS of fluorine are present in 5.35×1022 molecules of boron trifluoride?
Nitrogen dioxide gas is dark brown in color and remains in equilibrium with dinitrogen tetroxide gas, which is colorless.
2NO2(g) ⇌ N2O4(g)
When a light brown colored mixture of the two gases at equilibrium was moved from room temperature to a higher temperature, the mixture turned dark brown in color.
Which of the following conclusions about this equilibrium mixture is true?
This reaction is exothermic because the system shifted to the left on heating.
This reaction is exothermic because the system shifted to the right on heating.
This reaction is endothermic because the system shifted to the left on heating.
This reaction is endothermic because the system shifted to the right on heating.
Answer:
This reaction is exothermic because the system shifted to the left on heating.
Explanation:
2NO₂ (g) ⇌ N₂O₄(g)
Reactant => NO₂ (dark brown in color)
Product => N₂O₄ (colorless)
From the question given above, we were told that when the reaction at equilibrium was moved from room temperature to a higher temperature, the mixture turned dark brown in color.
This simply means that the reaction does not like heat. Hence the reaction is exothermic reaction.
Also, we can see that when the temperature was increased, the reaction turned dark brown in color indicating that the increase in the temperature favors the backward reaction (i.e the equilibrium shift to the left) as NO₂ which is the reactant is dark brown in color. This again indicates that the reaction is exothermic because an increase in the temperature of an exothermic reaction will shift the equilibrium position to the left.
Therefore, we can conclude that:
The reaction is exothermic because the system shifted to the left on heating.
The reaction is exothermic and the equilibrium position shifted to the left hand side.
An exothermic reaction is one in which heat is given out. Hence, the equilibrium position moves towards the left when the temperature is increased in an exothermic reaction.
Given the reaction, 2NO2(g) ⇌ N2O4(g) the appearance of a dark brown gas at high temperature implies that the reaction is exothermic and the equilibrium position shifted to the left hand side.
Learn more about exothermic reaction: https://brainly.com/question/15308590
What is the Law of Octaves?
A. The rule used to compose a poem of eight lines
B. Law describing the special properties of elements within eight electrons in the outer shell.
C. Each note has a series of eight sub notes increasing in variation between it and the next notes.
D.When ordered by atomic mass every eight elements has similar properties
i believe the answer would be D. When ordered by atomics mass every eighth element has similar properties.
air is made up of different gasses such as oxygen nitrogen and carbon dioxide. which statement best describes these three components of air?
-they are all classified as pure substances
-they cannot react with another substance
-they are chemically bonded to one another
-they can be classified as elements
Answer:
They are chemically bonded to one another
Answer:
they can be classified as elements
Directions: Fill in the blanks to complete the idea. 1. Constellations are group of that form pattems in the night sky 2. Ursa Major, Cassiopeia, and Orion are some common 3. Stars are used to tell and time, predict weather, and to serve as birth sign
PASAGOT PO NG MAAYOS
KAILANGAN LANG PO
BRAINLIEST+FOLLOW+HEART+POINT
BAD ANSWER-REPORT
1. Constellations are group of stars that form pattems in the night sky
2. Ursa Major, Cassiopeia, and Orion are some common constellations.
3. Stars are used to tell directions and time, predict weather, and to serve as birth sign.
What element has 9 electrons, and 11 neutrons?
fluorineelement has 9 electrons, and 11 neutrons
the molar mass of oxygen(O2) is 32g. what is the mass of 1.05*10^25 molecules of O2
Answer:
3.36×10²⁶ g
Explanation:
Molar mass ( O2) = 32g/mol
mole(O2) = 1.05×10²⁵mol
Mass(O2) = ?
mole(n)= mass(m)/Molar mass(M)
n×M = m
1.05×10²⁵ mol × 32g/mol = mass
mass= 3.36×10²⁶ g
The reversible reaction, 4HCl(g) + Si (s) ⇌ SiCl4 (l) + 2H2 (g) , would be classified as a ______________ reaction.
exothermic
endothermic
homogeneous
heterogeneous
Answer:
endothermic
Explanation:
endothermic reactions absorb heat from their surroundings, in this reaction the reactants are gas and solid and the products are liquid and gas, implying heat was absorbed to turn a solid to a liquid.
Which of the following correctly orders the types of radiation from the LONGEST wavelength to the SHORTEST wavelength?
A. Green Visible Light, Red Visible Light, Blue Visible Light, Ultraviolet
B. Microwave, Orange Visible Light, Ultraviolet, Violet Visible Light
C. Red Visible Light, Infrared, Microwaves, Radio waves
D. Microwave, Blue Visible Light, Ultraviolet, Gamma
Answer:
For the wavelenth of light spectrum, I believe the order would be red visible light, infrared, microwaves and radio waves.
At a temperature of -25 °C, a sample of gas in a rigid container exerts a pressure of 55.8 kPa. At what temperature will the pressure reach 145 kPa?
The required temperature of the gas sample is -64.96 °C.
What is ideal gas equation?Ideal gas equation gives idea about the behavior of gas at different condition & represented as:
PV = nRT.
From the above equation it is clear that relation between temperature and pressure for this question is:
P₁/T₁ = P₂/T₂, where
P₁ & T₁ are the initial pressure and temperature.
P₂ & T₂ are the final pressure and temperature.
On putting values, we get
T₂ = (145)(-25) / (55.8) = -64.96 °C
Hence required temperature of the sample is -64.96 °C.
To know more about ideal gas equation, visit the below link:
https://brainly.com/question/1056445
#SPJ2
How many mm of 0.200 M FeCl3 are needed to react with an excess of K2S to produce 2.75 g of Fe2S3 if the percent yield for the reaction is 65.0%?
Answer:
130 mL
Explanation:
2FeCl3(aq) + 3K2S(aq) -----> Fe2S3(s) + 6KCl(aq)
Percent yield = actual yield/theoretical yield × 100
actual yield = 2.75 g
Theoretical yield = x
65= 2.75/x × 100
x= 2.75 × 100/65
x= 4.2 g
Number of moles of FeCl3 = mass/molar mass = 4.2 g/ 162.2 g/mol = 0.026 moles
Then;
n= CV
n= number of moles
C= concentration
V= volume
V= n/C
V= 0.026 moles/ 0.200 M
V= 0.13 L or 130 mL
Liquid octane (CH3(CH2)CH3) reacts with gaseous oxygen gas(O2) to produce gaseous carbon dioxide(CO2) and gaseous water (H2O). What is the theoretical yield of carbon dioxide formed from the reaction of 27.4g of octane and 77.8g of oxygen gas?
Answer:
The theoretical yield of carbon dioxide formed is 68.4 grams CO2
Explanation:
Step 1: Data given
Liquid octane = C8H18
gaseous oxygen gas = O2
gaseous carbon dioxide = CO2
gaseous water = H2O
Mass of octane = 27.4 grams
Molar mass of octane = 114.23 g/mol
Mass of oxygen = 77.8 grams
Molar mass of oxygen = 32.0 g/mol
Step 2: The reaction
2C8H18(l) + 25O2(g) → 16CO2(g) + 18H2O(g)
Step 3: Calculate number of moles
Moles = mass / molar mass
Moles of octane = 27.4 grams / 114.23 g/mol
Moles of octane = 0.240 moles
Moles of oxygen = 77.8 grams / 32.0 g/mol
Moles of oxygen = 2.43 moles
Step 4: Calculate the moles of the products
For 2 moles of octane we need 25 moles of O2 to produce 16 moles of CO2 and 18 moles H2O
O2 is the limiting reactant. It will completely react. (2.43 moles).
There will react 2.43/12.5 = 0.194 moles
There will remain 0.240 - 0.194 = 0.046 moles of octane.
There will be produced:
16/25 * 2.43 = 1.555 moles of CO2
18/25 * 2.43 = 1.750 moles of H2O
This is:
1.56 moles * 44.01 g/mol = 68.4 grams CO2
1.750 moles * 18.02 g/mol = 31.5 grams H2O
The theoretical yield of carbon dioxide formed is 68.4 grams CO2
What is the frequency of an electromagnetic wave with a wavelength of 1.0 x 10' m?
a. 3.3 x 104 Hz
1.0 x 101 Hz
b. 3.0 x 10 Hz
d. 3.0 x 103 Hz
c.3.0 x 103 Hz
What type of soil has the finest of all the soil particles, measuring fewer than 0.002 millimeters in size?
Answer:
Clay soil
Explanation:
There are basically three types of soil namely: Sandy soil, clayey soil and loamy soil. Each of this soil type possess their own distinguishing characteristics. For example, on the basis of particle size and texture, CLAY SOIL possesses the smallest and finest particles.
Particles in a clay soil weighs lesser than 0.002 millimeters (mm) in size, making it have a high water holding or retention capacity.
If you produce 35.7 grams of sodium chloride how many molecules of Chlorine gas were
needed?
2Na + Cl2 --> 2NaCl
(PLS HELP ASAP)
Explanation:
I did it in steps to help u to understand :)
Which of the following elements is the largest in size?
A) O
B) He
C) K
ODH
Answer:
C) K
Explanation:
K has an electron configuration of 2.8.8.1
