Answer:
An atom of an element that exhibits typical metallic properties, being typically shiny, with high electrical and thermal conductivity. ... A metal may be a chemical element such as iron; an alloy such as stainless steel; or a molecular compound such as polymeric sulfur nitride.
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
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
calculate the final pressure of a gas that is expanded from 725cm³ at 30C and 1.19 atm to 1.12cm³ at 43C
Answer:
Final pressure, P2 = 1088.89 atm
Explanation:
Given the following data;
Initial volume, V1 = 725 cm³Initial temperature, T1 = 30°CInitial pressure, P1 = 1.19 atmFinal volume, V2 = 1.12 cm³Final temperature, T2 = 43°CTo find the final pressure (P2), we would use the combined gas law.
Mathematically, the combined gas law is given by the formula;
[tex] \frac {PV}{T} = k [/tex]
[tex] \frac {P_{1}V_{1}}{T_{1}} = \frac {P_{2}V_{2}}{T_{2}} [/tex]
Substituting into the formula, we have;
[tex] \frac {1.19*715}{30} = \frac {P_{2}*1.12}{43} [/tex]
[tex] \frac {850.85}{30} = \frac {P_{2}*1.12}{43} [/tex]
[tex] 28.3617 = \frac {P_{2}*1.12}{43} [/tex]
Cross-multiplying, we have;
[tex] 28.3617 * 43 = 1.12P_{2} [/tex]
[tex] 1219.5531 = 1.12P_{2} [/tex]
[tex] P_{2} = \frac {1219.5531}{1.12} [/tex]
Final pressure, P2 = 1088.89 atm
For a reaction, AH = 176 kJ/mol and A SO = 0.285 kJ/(K•mol). At what
temperatures is this reaction spontaneous?
A. At no temperature
B. T< 50 K
C. T> 617 K
D. T< 617K
What is the equilibrium constant of pure water at 25°C
True or false, If an atom is charged negative, it contains more electrons than protons.
Answer:
True
Explanation:
An atom would carry more protons if positively charged, an equal amount of both protons and electrons if neutral, and more electrons if charged negative.
What element has 9 electrons, and 11 neutrons?
fluorineelement has 9 electrons, and 11 neutrons
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.
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)
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.
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
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
what is the atomic number of an atom that has 20 protons and 20 neutrons
Answer:
20
Explanation:
Hi there!
We need to find the atomic number of an atom that has 20 protons and 20 neutrons
the atomic number of an atom is equivalent to the amount of protons an atom has, as the number of protons determines what element an atom is.
Since the atom has 20 protons, the atomic number of the said atom is 20
Hope this helps!
can someone do this step by step
Answer:
No
Can't understand.
Pls follow me and Mark as brainliest Plsssssssss.
What is water cycle ?
Answer:
is the water that passes through the carbon cycle of atmosphere
The electrolysis of water forms H2 and O2. 2H2O Right arrow. 2H2 O2 What is the percent yield of O2 if 10.2 g of O2 is produced from the decomposition of 17.0 g of H2O
Answer:
67.5%
Explanation:
Step 1: Write the balanced equation for the electrolysis of water
2 H₂O ⇒ 2 H₂ + O₂
Step 2: Calculate the theoretical yield of O₂ from 17.0 g of H₂O
According to the balanced equation, the mass ratio of H₂O to O₂ is 36.04:32.00.
17.0 g H₂O × 32.00 g O₂/36.04 g H₂O = 15.1 g O₂
Step 3: Calculate the percent yield of O₂
Given the experimental yield of O₂ is 10.2 g, we can calculate its percent yield using the following expression.
%yield = (exp yield / theoret yield) × 100%
%yield = (10.2 g / 15.1 g) × 100% = 67.5%
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.
What is the weight on Earth of an apple with mass 150g?
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
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 HCPCS Level II code for the compounded concentrated form of 0.5 mg Levalbuterol HCL when inhaled
Answer:
aefhfcjd
Explanation:
How many GRAMS of fluorine are present in 5.35×1022 molecules of boron trifluoride?
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
Define fermentation and how alcohol is produced. Describe distillation, the process used in forming " spirits".
Answer:
Fermentation is where all alcohol is created, distillation is where the alcohol is separated and removed. In order for fermentation to occur, two things are needed: a raw material in liquid form that contains sugar, followed by the addition of yeast.
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
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 :)
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
a que llamamos niveles y subniveles de energia?
Answer:
agua
Explanation:
por que estamos en la planeta
As a pure element the oxidation number of zinc is ________, but in compounds such as ZnCO3 its oxidation number is ________. Group of answer choices
Answer:
0, +2
Explanation:
As a pure element, any element or simple compound has an oxidation number of 0. This makes it a lot easier, and can be applied for almost any element or compound that uses one atom, like F2, O3, Zn, Fe, etc. However, in compounds, Zinc's oxidation number tends to be +2, and this is just a rule that I memorized when I learned this topic. Please let me know if you still need help and I hope you understood!
As a pure element, the oxidation number of zinc is zero, but in compounds such as [tex]ZnCO_3\\[/tex] its oxidation number is +2.
What is the oxidation number?Oxidation number also called oxidation state, is the total number of electrons that an atom either gains or loses in order to form a chemical bond with another atom.
As a pure element, any element or simple compound has an oxidation number of 0. This makes it a lot easier and can be applied for almost any element or compound that uses one atom, like [tex]F_2[/tex], [tex]O_3[/tex], Zn, Fe, etc.
However, in compounds, Zinc's oxidation number tends to be +2.
Learn more about the oxidation number here:
https://brainly.com/question/10079361
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