Answer:
1.8×10²² atom of Rn contain 0.03 moles of Rn.
Explanation:
Given data:
Number of atoms of Rn = 1.8×10²² atoms
Number of moles = ?
Solution:
we will solve this problem through Avogadro number.
It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance. The number 6.022 × 10²³ is called Avogadro number.
For example,
1 mole of Rn = 6.022 × 10²³ atoms of Rn
1.8×10²² atoms of Rn × 1mol / 6.022 × 10²³ atoms of Rn
0.3×10⁻¹ moles of Rn
0.03 moles of Rn
g The free energy change of the reaction A (g) ---> B(g) is zero under certain conditions. The STANDARD Free energy change of the reaction is -42.5 kJ. Which of the following statements must be true about the reaction described here? A) The concentration of the product is greater than the concentration of the reactant. B) The reaction is at equilibrium. C) The concentration of the reactant is greater than the concentration of the product.
Answer:
The reaction is at equilibrium.
Explanation:
In thermodynamics, the Gibbs free energy is a term used traditionally to refer to the available or useful work that can be obtained from a thermodynamic system.
Gibbs free energy is a measure of the chemical potential that a reaction has left to do work. Hence, if the free energy is zero, then the reaction has attained equilibrium, and there is no more work to be done
The statement that should be true related to the reaction should be that it should be at equilibrium.
What is Gibbs free energy?In terms of thermodynamics, this energy should be applied for the availability or the useful work that should be obtained via the system of thermodynamics.
Also, it determined the chemical potential where the reaction has left for doing the work. Also in the case when the free energy should be zero so here the reaction should be attained the equilibrium.
hence, the option b is correct.
Learn more about energy here:
What element has an atomic mass 4?
Answer:
Helium has atomic mass 4.002602.
So the answer to yr question is helium.
It is expected that as the temperature goes up by the above method, frozen carbon dioxide will defrost and evaporate into the atmosphere, raising temperatures even more. Why would this be
Answer:
CO2 is a green house gas
Explanation:
CO2 is believed to act as a canopy over the earth's surface absorbing infrared (heat ray) from the earth and re-emitting it back to the earth.
By so doing, temperature is increased and more frozen CO2 will defrost causing even greater temperature rise.
The gradual rise in the earth's temperature is known as global warming.
plzzz help hahsbhd db question 5
Answer:
chemical reactions
Explanation:
Answer:
chemical reactions
Explanation:
Chemical reactions like weathering can cause rock and earth movement, plants grow from rain which is weathering, snow is weathering and cold winters is freezing water. I don't see how flowing water can contribute to weathering because in rivers, creeks, etc, always flowing. So if flowing water is always moving, it's not caused by weathering.
I EDITED MY ANSWER:
Physical weathering is caused by purely mechanical changes to the rock, while chemical weathering is caused by chemical reactions. The answer is chemical reactions
The reactants are
A
the substances present when the reactions begin.
B
the substances present when the reaction is complete.
C
the properties that change after the reaction.
D
the energy that is released or stored during the reaction.
pls, hurry!!!!!!!!!!!!!!!!
The rate of reaction in terms of the "rate law expression" includes the rate constant (kk), the concentration of the reactants, and the orders of the reaction with respect to the different reactants. Consider the following reaction: A+B→C+DA+B→C+D The initial concentrations of the reactants AA and BB are 0.200 MM and 0.350 MM, respectively. The rate of reaction is 0.060 M⋅s−1M⋅s−1, and the orders of the reaction, with respect to reactants AA and BB, are 1 and 2, respectively. Determine the rate constant (kk) for the reaction using the rate law. Express your answer in M−2⋅s−1M−2⋅s−1 to three significant figures.
Answer:
[tex]k=2.45M^{-2}s^{-1}[/tex]
Explanation:
Hello.
In this case, considering the given specific orders of reaction, we can write the rate law as:
[tex]r=k[A][B]^2[/tex]
Thus, considering the concentrations of A and B to be 0.200 M and 0.350 M respectively and a rate of 0.060 M/s, the rate constant turns out:
[tex]k=\frac{r}{[A][B]^2}\\ \\k=\frac{0.060M/s}{(0.200M)(0.350M)^2} \\\\k=2.45M^{-2}s^{-1}[/tex]
This is what we know as a third-order reaction since the specific orders both add to 3.
Best regards.
An object has a mass of 35.00 grams. On Luixandras balance it weighs 33.95 grams. What is the percent error in this balance?
Answer:
The answer is 3 %Explanation:
The percentage error of a certain measurement can be found by using the formula
[tex]P(\%) = \frac{error}{actual \: \: number} \times 100\% \\ [/tex]
From the question
actual mass = 35 g
error = 35 - 33.95 = 1.05
We have
[tex]p(\%) = \frac{1.05}{35} \times 100 \\ [/tex]
We have the final answer as
3 %Hope this helps you
The diagram below shows a lithium atom. Which of the following correctly lists the particles in a lithium atom? *
Captionless Image
A. 3 protons, 4 neutrons, 3 electrons
B. 3 protons, 3 neutrons, 4 electrons
C. 4 protons, 4 neutrons, 3 electrons
D. 4 protons, 3 neutrons, 4 electrons
If 65,000 J of energy were transferred to 450 g of water at 20˚C. What would have been the final temperature of the water?
Answer:
500g
Explanation:
Answer:Suppose that during the Icy Hot lab that 65 KJ of energy were transfered to 450 g of water at 20 degrees C. What would have been the final temerpatur
Explanation:
Why are mass and weight different measurements?
Explanation:
Mass, is amout of matter contained in body
it value remain constant
it cannot be zero
weight is gravitational force which attract body towards centre of earth
it value changes
it can be zero
Which factor is most important to consider when evaluating a journal article about global warming? Is the article long enough? Does the article contain facts or only opinions? Did the author of the article use complex, scientific words? Does the author of the article have a doctorate degree?
Answer:
Does the article contain facts or only opinions
Got it right on edg.
Answer:
B) Does the article contain facts or only opinions?
Explanation:
Which group is the most reactive?
*
Alkaline Earth Metals
Alkali metals
Noble Gases
Lanthanides
Answer:
alkali metals- Group 1
Explanation:
they have less valence electrons and therefore are more reactive
Viktor tests a solution with a strip of blue litmus paper. The paper turns pink. The solution is a _____.
weak acid
weak base
strong acid
strong base
Answer:
The solution is acidic.
Explanation:
Mass is a unique property of any property.
A ________________ causes a __________________ heat transfer rate.
Answer:
A smaller temperature difference causes a smaller heat transfer
Explanation:
The greater the temperature difference, the greater the rate at which heat transfers.
what do you mean by the region or space that an electron revolves the nucleus in an atom?
An atomic orbital is a mathematical feature describing the region and wave-like behavior of an electron in an atom. This characteristic can be used to calculate the opportunity of finding any electron of an atom in any precise location across the atom's nucleus.
What's the vicinity of space in which there's a high opportunity of locating an electron?An atomic orbital is regularly idea of as a location of space wherein there is an excessive opportunity of finding an electron. Every energy level corresponds to an orbital of a one-of-a-kind form, which describes wherein the electron is probable to be observed.
Learn more about atomic orbital here: https://brainly.com/question/20319149
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Why does water vapor
condense at higher
elevations?
A. cooling causes condensation
B. faster particle activity
C. due to a chemical change
D. due to a chemical reaction
Answer:
A. cooling causes condensation
Explanation:
air is cooler at higher altitude in the troposphere.
What body of water is south of Constantinople? Atlantic Ocean Indus River Black Sea Mediterranean Sea
How much heat is required to raise the temperature of 93.5 gg of water from its melting point to its boiling point
Answer:
39270 J
Explanation:
The quantity of heat required to raise the temperature of a substance from its initial temperature to its final temperature is given by:
Q = mCΔT
m = mass of substance, C = specific heat capacity of substance, ΔT = temperature change = final temperature - initial temperature
Melting point = 0°C, boiling point = 100°C, m = 93.5 g = 0.0935 g, ΔT = boiling point - melting point = 100 - 0 = 100°C, C = 4200 J/kg°C
Q = mCΔT
Q = 0.0935 × 4200 × 100 = 39270 J
What do metalloids and non metals have in common
Answer:
Metalloids are brittle like Non-Metals
Explanation:
what are proteins? (simple definition please)
Proteins are large biomolecules, or macromolecules, consisting of one or more long chains of amino acid residues. Hope this helps!
Answer:
Proteins are carbohydrates that come from nutritious food.
They are one of the four main carbohydrates.
This is a simple definition of the word proteins.
Hope this helps!
What atomic symbol completes this reaction?
238 234.
U →
Th + ?
90
92
Answer:
Correct option is ₂⁴He
Explanation:
Uranium-238 undergo alpha decay and produce Th-234 and alpha particle.
₉₂U²³⁸ → ₉₀Th²³⁴ + ₂He⁴ + energy
Alpha radiations are emitted as a result of radioactive decay. The atom emit the alpha particles consist of two proton and two neutrons. It is also called helium nuclei. When atom undergoes the alpha emission the parent atom converted into the atom having mass number less than 4 and atomic number less than 2 as compared to parent atom.
Properties of alpha radiation:
Alpha radiations can travel in a short distance.
These radiations can not penetrate into the skin or clothes.
These radiations can be harmful for the human if these are inhaled.
These radiations can be stopped by a piece of paper.
All matter has thermal energy because atoms are constantly
All matter has thermal energy because atoms are constantly in motion, due to motion all matter possess a kinetic energy. The total kinetic energy is known as thermal energy.
What is kinetic energy?The kinetic energy of an object is the energy that it possesses due to its motion. It is defined as the work needed to accelerate a body of a given mass from rest to its stated velocity. Having gained this energy during its acceleration, the body maintains this kinetic energy unless its speed changes
Thermal energy and temperature are closely related. Both reflect the kinetic energy of moving particles of matter. However, temperature is the average kinetic energy of particles of matter, whereas thermal energy is the total kinetic energy of particles of matter.
It increases or decreases only when the velocity changes, heavier objects, It can transform into other types of energy. It will occur regardless of the moving object's direction of travel.
Thus, all matters has thermal energy because atoms are constantly in motion.
To find more about Matter, refer the link below:
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4. A method in which two or more components of different sizes are sepa-
rated from a mixture on the basis of the difference in their sizes.
Answer: Sieving
Im 100% sure its the answer!
2.6
+
3.78
How do you solve this problem
Answer:
6.38
Explanation:
line up the decimals
it helps to add another 0 to 2.6 so that you can align them better
1
2.60
+ 3.78
= 6.38
8 + 0 = 8
6 + 7 = 13; write 3 and carry the one over above the 2 in 2.60
2 + 3 + 1 = 6
I tried my best to show it through text.
how many seconds is in 1 year
Explanation:
hope it helps :)
Which of the following can be broken down by chemical processes but not physical processes?
elements
compounds
all of these
mixtures
Answer:
Elements and compounds
Explanation:
Elements and compounds, mixtures are not chemically bonded and can be physically seperated
Investigating physical and chemical changes takes a plan. Which of the following
are part of planning? Select all that apply.
A. knowing the results of the investigation
B. listing the materials and tools that are needed
C. filling out a data table with the results
D. writing down the procedure for the investigation
E. making sense of what happened to explain it
Answer:
D e
Explanation:
Which of the following statements is/are correct? i. Principal energy levels are identified by the letters s, p, d, and f. ii. Principal energy levels appear in both the quantum mechanical model of the atom and the Bohr model of the atom. iii. In general, n = 1 is at lower energy than n = 2, and n = 2 is lower than n = 3, and so on. iv. The principal energy level is related to electron spin. a. i only b. iv only c. i and ii d. ii and iii e. iii and iv
Answer:
d. ii and iii
Explanation:
Both the Bohr model and the wave (quantum) mechanical models of the atom recognize the principal quantum number n. The principal quantum number shows the shell or energy level where an electron may be found.
The energy levels are arranged in increasing order of magnitude. That is n=1 >n=2=n=3 etc
How are gases and liquids different from each other? O A. Liquids can change volume, and gases cannot. B. Gases can change shape, and liquids cannot. C. Liquids can change shape, and gases cannot. D. Gases can change volume, and liquids cannot.
Answer:
d
Explanation:
d is the right answer since gases do not have definite shape and volume and liquids have definite volume. so liquid cannot change its volume but gas can