Answers
Sample left = 6.25 g
The percentage = 6.25%
Further explanationGiven
t1/2 = half-life = 3.8 days
t = decay time = 15.2 days
No = initial sample = 100 g
Required
Nt = final sample left
The percentage
Solution
General formulas used in decay:
[tex]\large{\boxed{\bold{N_t=N_0(\dfrac{1}{2})^{t/t\frac{1}{2} }}}[/tex]
Input the value :
[tex]\tt N_t=100.\dfrac{1}{2}^{15.2/3.8}\\\\N_t=100.\dfrac{1}{2}^4\\\\N_t=6.25~g[/tex]
The percentage : Nt/No
6.25 : 100 = 6.25%
Related Questions
Explain how to use the ATOMIC NUMBER and ATOMIC MASS, of any element to calculate the amount of neutrons located in the nucleus of a atom
Answers
Explanation:
Atomic Number :
It only explain number of protons and electrons in nuclous
Atomic Mass :
Atomic mass tell how much neutrons are present in atom.
Answer:
[tex]\underline{ \boxed{atomic \: number = atomic \: mass - neutron \: number}} \\ \underline{ \boxed{atomic \: mass = proton \: number + neutron \: number}} \\ \underline{ \boxed{neutron \: number = atomic \: mass - proton \: number}}[/tex]
Explanation:
[tex] \underline{ \boxed{1}} \\ ATOMIC \: NUMBER = (atomic \: mass \: number\: - neutron \: number \: )\\ (which \: is \: same \: as ) = \: \underline{ \boxed{proton \: number}}\\ \\ \underline{ \boxed{2}} \\ ATOMIC \: MASS = (proton \: number \: + neutron \:number) \\ (is \: same \: as ) = \: \underline{ \boxed{sum \: of \:atomic \: nuclear \: content}} \\ \\ \underline{ \boxed{3}} \\ neutrons = (atomic \: mass \: number - proton \: number) \\ [/tex]
What are the half-reactions for a galvanic cell with aluminum and gold
electrodes?
Answers
Answer:
A
Explanation:
In a galvanic cell, energy is produced by spontaneous chemical processes.
The cathode and anode of this cell will depend on the relative position of the two metals in the electrochemical series.
Aluminium is higher in the electrochemical series so aluminium will be the anode. Silver is lower in the electrochemical series so silver will be the cathode.
Recall that oxidation (electron loss) occurs at the anode while reduction (electron gain) occurs at the cathode.
The half-reactions for the galvanic cell with aluminum and gold electrodes is [tex]\mathbf{Al_{(s)}\to Al^{3+} _{(aq) } + 3e^- \ and \ Au^+_{(aq)} +e^- \to Au_{(s)}}[/tex]
Galvanic cells are electrochemical cells that generate electrical energy by the spontaneous activity in the oxidation-reduction (redox) reaction process.
The position of the metals if they are going to be at the cathode or at the anode relatively depends on the position with which they find themselves in the electrochemical series. The higher metal will be the anode and the lower metal in the electrochemical series will be the cathode.
Since aluminum is higher than gold on the electrochemical series, then:
Aluminum = anode (oxidation of aluminum from solid to aqueous state)Gold = cathode (reduction of gold from aqueous to solid-state)Therefore, the half-reactions for the galvanic cell with aluminum and gold electrodes is [tex]\mathbf{Al_{(s)}\to Al^{3+} _{(aq) } + 3e^- \ and \ Au^+_{(aq)} +e^- \to Au_{(s)}}[/tex]
Learn more about Galvanic cells here:
https://brainly.com/question/25606597
Please help due soon fill in the blanks will give brainliest
Answers
Answer:
Proton has positive charge (+) and located in nucleus
Electron has negative charge (-) and located in electron cloud
Neutron has neutral charge (0) and located in nucleus
Which ones are elements, compounds I’ll give brainliest.
Answers
how many oxygen atoms are in 10.0g of 2Al2 CO3 3
Answers
Answer:
0.776 ×10²³ atoms of oxygen
Explanation:
Given data:
Mass of Al₂CO₃ = 10.0 g
Number of atoms of oxygen = ?
Solution:
Number of moles of Al₂CO₃:
Number of moles = mass/molar mass
Number of moles = 10.0 g/233.99 g/mol
Number of moles = 0.043 mol
1 mole of Al₂CO₃ contain 3 mole of oxygen.
0.043 ×3 mol = 0.129 mol
Number of atoms of oxygen:
1 mole contain 6.022×10²³ atoms
0.129 mol × 6.022×10²³ atoms / 1mol
0.776 ×10²³ atoms of oxygen
How can you ensure the chemical reaction produces the right amount of heat in a hot pack without hurting you?
Answers
Answer:
Heat packs that contain iron and water packets: Exposing the solution to air results in the oxidation of the iron (creates rust). The oxidation of the iron is an exothermic process. Heat packs that contain supersaturated sodium acetate: These are reusable, the packs are boiled to dissolve sodium acetate.
Explanation:Thanks for asking question
Plzzzz help I’ve been with this for like 2 hours Ik it’s sad my momma didn’t give me a brain
Answers
Answer:
12- cold air is more dense then hot
13- Make days warmer (sorry if thats wrong!! :)
Answer:
cold air is more dense then hot
Make days warmer
Explanation:
What is a sign that a person may be abusing drugs?
A a change in mood and behavior
B avoiding friends and family members
C a drop in grades and a loss of interest in activities
D all of the above
Answers
Answer:
answer is a because drugs do so to the person.
Fossils can be found all over the world, often in layered rock formations. To determine the age of the rock layers within an
area, geologists and paleontologists use a technique called radiometric dating. Determining the age of a rock layer allows
scientists to determine the age of the fossils within it.
Some of the more exciting fossil discoveries are of dinosaurs, which existed on Earth between 230 and 65 million years
ago. Examine this map e. Click the map to zoom in, and drag the magnifying glass for a closer look. The map shows
where prehistoric rocks formed during the Triassic, Jurassic, and Crustaceous time periods, the same periods when
dinosaurs walked on Earth. Based on the map, what is the closest location to you where dinosaurs are likely to have lived?
Answers
Answer: Western USA.
Answer:
the answer is the question itself
Explanation:
An element is a specific type of atom (true or false)
Answers
Answer:
True
Explanation:
An element is pure substance that conatin only one type of atom
Answer:
true
Explanation:
the element hydrogen is made from atom
According to the Bohr model of the atom, energy is emitted as light when electrons
O fall back down to a lower energy level
O jump up to a higher energy level
are absorbed into the nucleus
O are ejected from the nucleus
Answers
Answer:
After jumping to the higher energy level also called the excited state the excited electron would be in a less stable position, so it would quickly emit a photon to relax back to a lower, more stable energy level.
what is a displacement reactions
Answers
A displacement reaction is the one wherein the atom or a set of atoms is displaced by another atom in a molecule. For instance, when iron is added to a copper sulphate solution, it displaces the copper metal.
A + BC → AC + B
The above equation exists when A is more reactive than B.
A and B have to be either:
Halogens where C indicates a cation.
Different metals wherein C indicates an anion.
[tex]\textsf{what is a displacement reactions? }[/tex]
Answer:[tex]\large \underbrace{ \underline{ \sf Displacement \: reaction}}[/tex]
The reaction in which more reactive element replace a less reactive element from its compound is called displacement reaction.
Ex:-
[tex]\bold{\large Zn+HCl \longrightarrow ZnCl_2+H_2}[/tex]
Why do scientists use the scientific method?
Answers
Answer:
I think that the first one is right(A)
A student noticed that the size of the hot pack becomes bigger when magnesium sulfate reacts with water. She thinks that more atoms are produced that make the hot pack grow bigger. Do you agree? Explain.
Answers
Answer:
Disagree with the suggestion based on the hygroscopic nature of anhydrous magnesium sulfate
Explanation:
Magnesium sulfate in the anhydrous form is a drying agent. A drying agent salts of inorganic compounds that has the capability of absorbing water to become hydrated, when placed in the presence of a wet surface or moist air
Anhydrous magnesium sulfate is therefore hygroscopic such that it absorbs water from the atmosphere and becomes hydrated and increases in size as its volume is increased according to the following chemical equation
MgSO₄(s) + 7H₂O(l) → MgSO₄·7H₂O(s)
The molar mass of anhydrous magnesium sulfate = 120.366 g/mol
The molar mass of the heptahydrate = 246.47 g/mol
Therefore, the mass of the magnesium sulfate doubles when it forms the heptahydrate, and the magnesium sulfate grows bigger.
2. Convert 120.02g of FrBiz to moles
a. 0.19 moles
b. 5.34 moles
c. 76,932.82 moles
Answers
Answer:
PRACTICE MULTIPLE CHOICE QUESTIONS FROM UNIT 10
1.) A cylinder is filled with 2.00 moles of nitrogen, 3.00 moles of argon, and 5.00 moles of helium. If
the gas mixture is at STP, what is the partial pressure of the argon?
(A) 152 torr (B) 228 torr (C) 380. torr (D) 760. torr
2.) Compared to the average kinetic energy of 1 mole of water at 0 oC, the average kinetic energy
of 1 mole of water at 298 K is
(A) the same, and the number of molecules is the same
(B) the same, but the number of molecules is greater
(C) greater, and the number of molecules is greater
(D) greater, but the number of molecules is the same
3.) If the pressure on a given mass of gas in a closed system is increased and the temperature
remains constant, the volume of the gas will
(A) decrease (B) increase (C) remain the same
4.) Which gas has approximately the same density as C2H6 at STP?
(A) NO (B) NH3 (C) H2S (D) SO2
5.) At a temperature of 273 K, a 400. milliliter gas sample has a pressure of 760. millimeters of
mercury. If the pressure is changed to 380. millimeters of mercury, at which temperature will
this gas sample have a volume of 551 milliliters?
(A) 100 K (B) 188 K (C) 273 K (D) 546 K
Get the answers to these questions
Back to the Unit 10 Old Tests Pag
24.Og sample of carbon contains how may moles?
Answers
Answer:
2 moles
Explanation:
1.9982182553889358 real number but round up to 2
What do all volcanos emit?
Answers
Answer:
By far the most abundant volcanic gas is water vapor, which is harmless. However, significant amounts of carbon dioxide, sulfur dioxide, hydrogen sulfide and hydrogen halides can also be emitted from volcanoes.
HELP! I will mark you as Brainliest
How does the energy of a wave relate to the wave’s amplitude?
The more energy a wave has, the smaller the amplitude is. This is because they do not have a direct relationship.
The more energy a wave has, the larger the amplitude is. This is because they do not have a direct relationship.
The more energy a wave has, the smaller the amplitude is. This is because they have a direct relationship.
The more energy a wave has, the larger the amplitude is. This is because they have a direct relationship.
Answers
Answer:
They have direct relationship and larger wave energy.
Answer:
Its D on edge
Explanation:
i took the test
The element with 12 protons in its nucleus is
a. magnesium
b. zinc
c. boron
d. carbon
Answers
Answer:
A.Magnesium
Explanation:
Answer:
magnesium
Explanation:
How many atoms are in 8.00 moles of potassium chromate?
Answers
Answer:
481.6x10^23
Explanation:
Answer:
[tex]\boxed {\boxed {\sf About \ 4.82 *10^{24} \ atoms \ K_2CrO_4}}[/tex]
Explanation:
To convert from moles to atoms, Avogadro's Number must be used.
[tex]6.022*10^{23}[/tex]This number tells us how many particles (atoms, molecules, ions. etc.) in 1 mole of a substance. In this case, it is atoms of potassium chromate (K₂CrO₄) in 1 mole.
[tex]6.022*10^{23} \ atoms \ K_2CrO_4 / 1 \ mol \ K_2CrO_4[/tex]
Use this number as a fraction.
[tex]\frac{6.022*10^{23} \ atoms \ K_2CrO_4}{1 \ mol \ K_2CrO_4}[/tex]
Multiply by the given number of moles (8.00).
[tex]8.00 \ mol \ K_2CrO_4 *\frac{6.022*10^{23} \ atoms \ K_2CrO_4}{1 \ mol \ K_2CrO_4}[/tex]
The moles of potassium chromate will cancel.
[tex]8.00 *\frac{6.022*10^{23} \ atoms \ K_2CrO_4}{1}[/tex]
The denominator of 1 can be ignored.
[tex]8.00 *(6.022 *10^{23} \ atoms \ K_2CrO_4)[/tex]
Multiply.
[tex]4.8176*10^{24} \ atoms \ K_2CrO_4[/tex]
The original measurement of moles (8.00) has 3 significant figures, so we must round our answer to 3 sig figs.
For the number we calculated, that is the hundredth place. The 7 in the thousandth place tells us to round the 1 up to a 2.
[tex]4.82 *10^{24} \ atoms \ K_2CrO_4[/tex]
There are about 4.82* 10²⁴ atoms of potassium chromate in 8.00 moles.
The diagram below shows the apparatus used to pass a current through copper
sulfate solution.
1 x
Positive electrode
Negative electrode
Copper sulfate solution
What is the name of component X in the diagram above?
point
Fuse
Switch
оооо
Ammeter
O Battery
Answers
i think the answer is b) i.e. Switch....
according to me ammeter and battery are already there...
What coefficient will balance the equation that is shown?
___ H2O → 2H2 + O2
Answers
Answer:
The coefficient is 2
Explanation:
count the Number of hydrogen and oxygen elements on both sides. They should be equal.
PLZ HELP !!!!!
Which statement correctly describes the main difference between body waves and surface waves?
Select one:
Surface waves are only longitudinal waves and body waves are only transverse waves.
Surface waves only travel across oceans and body waves travel across the Earth’s crust.
Surface waves are less damaging to man-made structures than body waves.
Surface waves travel across the Earth’s surface and body waves travel through the Earth’s interior.
Answers
Surface waves travel across the Earth’s surface and body waves travel through the Earth’s interior.
there you go :)
Give three examples of convection. PLEASE I AM BEING TIMED!!!
Answers
Choose the statements below that are correct regarding the nature of protons and neutrons. Choose ALL statements that are correct.
a. protons and neutrons are found around the outer edge of the atom
b. protons and neutrons have approximately the same charge
c. protons and neutrons are found in the nucleus
d. protons and neutrons have approximately the same mass
Answers
Answer:
c. protons and neutrons are found in the nucleus
d. protons and neutrons have approximately the same mass
Explanation:
There are three fundamental particles within an atom which are the protons, neutrons and electrons.
The protons are the positively charged particles within an atom
Neutrons do not carry any charges
Electrons are the negatively charged particles.
Both the protons and neutrons occupy the tiny nucleus at the center of the atom. The electrons moves round the nucleus through the orbital space. The mass of the protons and neutrons are similar and are assumed to be approximately the same.A solid turning to a liquid is called..?
Answers
Answer:
A physical change.
Explanation:
Have a wonderful day!
Much of the thermal energy within the Earth comes from atoms that decay. What is another major source of thermal energy within the
Earth?
A. gravitational energy left over from the formation of the Earth
B. thermal energy from the decay of dead plants and animals
c. thermal energy trapped by clouds and water vapor in the atmosphere
D. thermal energy absorbed by the Sun at the Earth's crust
Answers
Geothermal energy is heat produced by the Earth itself. It is a resource that may be gathered for human use and is renewable.
The correct option is (D) Thermal energy absorbed by the Sun at the Earth's crust
The friction and gravitational attraction that were produced when Earth was formed more than 4 billion years ago provide a modest amount of the core's heat. The continual production of heat on Earth, however, is mostly caused by the decay of radioactive isotopes like potassium-40 and thorium-232. From the surface to the core, the temperature of Earth increases with depth. The geothermal gradient is the term used to describe this progressive temperature variation. Rock that has partially melted is known as magma, which is gas- and bubble-filled. The lower crust and mantle both contain magma, which occasionally bubbles to the surface as lava.Nearby rocks and subsurface aquifers are heated by magma. Geysers, hot springs, steam vents, undersea hydrothermal vents, and mud pots are among ways that hot water can be emitted.They are all powered by geothermal energy. Their heat may be captured and used directly for heating, or their steam can be used to generate electricity.Learn more about the Geothermal energy with the help of the given link:
https://brainly.com/question/1061324
#SPJ1
how many moles of sodium are present in a sample of sodium having a mass of 137 g? (molar mass is 23.0g)
Answers
Answer:
5.95 moles
Explanation:
No of moles = given mass / molar mass
No of moles = 137/23
= 5.95 moles
If different atoms can come together to form living and nonliving things, why is there a limit to different combinations we encounter around the universe?
Answers
Explanation:
There is a limit to different things we encounter around the universe due to a lot of reasons.
Some combinations takes place under special conditions due to the activation energy barrier present.To overcome these barriers, some catalysts that are not readily available are needed. This reduces the combination of some atoms in nature.
Also, the right temperature and pressure conditions might not be present. For most reactions to occur, the right conditions must be made available by nature.This and many more reasons limits the combination of chemical substances.
There is a limit to different things we encounter around the universe due to a lot of reasons:
Some combinations takes place under special conditions due to the activation energy barrier present. To overcome these barriers, some catalysts that are not readily available are needed. This reduces the combination of some atoms in nature. Also, the right temperature and pressure conditions might not be present. For most reactions to occur, the right conditions must be made available by nature.So, for a chemical reaction to occur there are certain parameters that need to taken into consideration for a chemical reaction to actually takes place.
Learn more:
brainly.com/question/21568405
Lucy volunteers at an animal shelter, and she takes care of an orange tabby 1 point
cat and her kittens. Some of the kittens have orange markings, but some
have gray markings. What units of genetic material determine how living
things look?
Answers
Answer; the answer is variations
The unit of genetic material that determines how living things look is called variations, look below for more description.
What are genetic variations?Hereditary variety alludes to contrasts among the genomes of individuals from similar species. A genome is all the innate data — every one of the qualities — of a creature. Hereditary variety is the distinction in DNA successions between people inside a populace.
For example, the human genome contains somewhere close to twenty and 25 thousand qualities.
Find more information about Genetic variations here:
brainly.com/question/14926046