Astatine-210 has a half-life of 8.08 days. What fraction of a sample of astatine-210 is left unchanged after 16.16 days?
Answer:
0
Explanation:
Given parameters:
Half-life = 8.08days
Unknown:
What fraction is left unchanged after 16.16days = ?
Solution:
The half - life of a substance is the time taken for the half of a radioactive material to decay to half.
Day 0 Day 8.08 Day 16.16
100% 50% 0% Parent
0% 50% 100% Daughter
After 16.16 days, non of the original sample will remain unchanged.
What does the chemical formula show?
a) The number of elements in each molecule
b) The number of atoms in each molecule
c) How heavy the molecule is.
d) The elements in the molecule and the number of atoms of each one .
Answer:
A
Explanation:
You can eliminate C because you need to consult a periodic table to determine the mass (not the weight).
There are other answers you could use. The wording is awfully sloppy. D is an example of that. The elements part is true, the atoms part is not really true in all cases. For example NaCl is table salt and both the elements are ions, not atoms. Na is plus ion and Cl is minus one. B is wrong for the same reason.
I think in the end I would choose A. I think this is a very sly question. It is not really testing chemistry. It is testing how well you know your definitions.
What’s the best answer?
this is a lot of points and I will give brainlets for the correct answer
Answer:13132
Explanation:123123
CAN SOMEONE PLEASE HELP ME WITH THIS PLZ
Answer:
the pressure increases
who ran the control room chernobyl part 1
what happens to molecules when the temperature drops or lowers
A the molecules stop moving
B the molecules get closer together
C the molecules start moving faster
D the molecules become smaller
what are the 3 types of bonds in chemistry? and how can you tell when a chemical has that bond?
Answer:
Ionic bonding, Covalent bonding, Metallic bonding.
» My memory
A chemical bond is a lasting attraction between atoms, ions or molecules that enables the formation of chemical compounds. The bond may result from the electrostatic force of attraction between oppositely charged ions as in ionic bonds or through the sharing of electrons as in covalent bonds. » Wikipedia
a gas tank is under 1 atm pressure at room temperature. if the temperature halved,what will happen to the pressure
Answer:
The pressure will also be halved.
Explanation:
Gay-Lussac's law states that the relationship between temperature and pressure is directly proportional to each other. If the temperature goes up, so will the pressure.
Which one of the following statements about orbitals is INCORRECT?
1) orbitals are regions in space where one is likely to find an electron
2) orbitals can hold up to two electrons
3) orbitals can hold two electrons provided they are spinning in the same direction
4) s, p, d and f orbitals are possible
3) orbitals can hold two electrons provided they are spinning in the same direction
We define an orbital in chemistry as a region in space where there is a high probability of finding an electron.
Each orbital holds a maximum of two electrons which spin in opposite direction according to Pauli exclusion principle.
According to this principle no two electrons can have the same set of quantum numbers. As a result, the spin quantum numbers of two electrons in the same orbital must differ hence they spin in opposite directions.
https://brainly.com/question/19536139
How do you separate a mixture?
Answer:
We can seperate a mixture by various methods
Explanation:
Distillation, Evaporation, filtration and chromatography
what is always true of a week acid??????
A) It only partially dissociates in solution.
B) It does not dissolve in water.
C) It contributes only one proton.
D) It has been diluted with water.
Answer:
I'm pretty sure it's A
Explanation:
Answer:
for the a p e x quiz:
it dissociates completely in solution.
Explanation:
a p e x
The emission spectrum of iodine is shown below. A line spectra with 2 purple lines, 6 blue lines, 3 light blue lines, 3 green-blue lines, 6 green lines, 8 yellow lines, 6 orange lines and 8 red lines. Which is the absorption spectrum? A line spectra with 4 purple lines, 6 blue lines, 3 light blue lines, 5 green-blue lines, 6 green lines, 7 yellow lines, 3 orange lines and 14 red lines. A line spectra with 6 purple lines, 9 blue lines, 6 light blue lines, 3 green-blue lines, 6 green lines, 2 yellow lines, 5 orange lines and 10 red lines. A line spectra with 2 black lines in purple, 6 black lines in blue, 3 black lines in light blue, 1 black line in green-blue, 10 black lines in green, 8 black lines in yellow, 6 black lines in orange and 8 black lines in red. A line spectra with 4 black lines in purple, 8 black lines in blue, 6 black lines in light blue, 3 black line in green-blue, 10 black lines in green, 4 black lines in yellow, 4 black lines in orange and 12 black lines in red.
Answer:
it's b
Explanation:
The emission spectrum which is a line spectrum of iodine consists of 6 blue lines as it absorbs yellow light.
What is emission spectrum?Emission spectrum is defined as a spectrum of a chemical compound or substance composed of frequencies of electromagnetic radiation. Radiations which are emitted while electron make transition from higher to lower energy level.
Energy of photon is equal to the difference between the two energy states . There are many possible electronic transitions in an atom and every transition has a specific wavelength.
Collection of different transitions with respect to different wavelengths makes up an emission spectrum.Emission spectrum of each element is unique and therefore spectroscopy is used to identify elements which are present in different substances.
Learn more about emission spectrum,here:
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#SPJ5
Which electron notation is incorrect?
1s 2s 2p 3s 3p 10
1s 2s 2p 3s 3p3
1s2 282 2p 3s 3p6
Classify each organic compound based on the functional group it contains.
ether
carboxylic acid
ester
alcohol
Molecular Structure
Type of Compound
I-O-I
Η Ο
1 10
C-C-0-H
1
H
H
-I
H
II
H
1
H-C
1
H
H
1
-C
1
H
1
H
1
H
1
H
H
I
H-C
1
H
H H
I
C-0-C-H
1
1
H H
1
H-CC-O-H
1
H H
Answer:
H2C2O1
Explanation:
Answer:
Carboxylic Acid
Ester
Ether
Alcohol
Explanation:
Which number is the same as 4.8 x104
a. 0.00048
b. 480000
C. 48000
d. 480
Answer:
I'm Pretty Sure It Would Be C
Answer:
C it is yeah...°∆°
Explanation:
......
The diagram below shows the distance traveled by two light waves in 1 second.
Based on the diagram, which of these conclusions is correct?
The frequency of Wave 1 is double the frequency of Wave 2.
The frequency of Wave 2 is double the frequency of Wave 1.
The wavelength of Wave 1 is four times the wavelength of Wave 2.
The wavelength of Wave 2 is four times the wavelength of Wave 1.
Please help
Answer:
The frequency of Wave 2 is double the frequency of Wave 1.
Explanation:
Waves with higher frequencies have shorter wavelengths, and lower frequencies have longer wavelengths.
Calculate the number of moles in 7g of nitrogen gas
Answer:
0.2498mol[tex]N_{2}[/tex]Explanation:
7gN2 x [tex]\frac{1 mol}{2(14.01) g}[/tex]
=0.2498mol N2
Nitrogen gas has the formula [tex]N_{2}[/tex] so therefore that means you would have to multiply the mass in the molar by 2. To solve for the number of moles you need to cancel out the grams, you do this by using the molar mass of nitrgoen gas. You get the value on in the denominator from the periodic table (atomic mass of element). The grams will cancel out, leaving you with the number of moles when you divide 7/2(14.01).
A substance X reacts with ammonium nitrate to produce a gas that turns damp red litmus paper blue. X must therefore be:
a) A salt
b) A catalyst
c) An alkali
d) An acid
Answer:
option C is correct
Explanation:
litmus paper turns red in acidic solution and turns blue in alkaline solution and turns purple in neutral solution
I SWEAR THIS IS WAY TOO EASY, WHY AM I THAT STUPID, HELP ME AND ILL MARK U BRAINLIEST
Answer:
i think the first one is gravity and second one is rotation
Explanation:
Atoms of two different elements must have different
Answer:
Atoms of two different elements must have different atomic numbers.
Explanation:
pls help me!!!!!!!
what are the elements found within the inner core of the earth??
im getting graded for this!! tyyyy
Answer:
Explanation:
iron
Consider the balanced equation below.
Upper P Upper C l Subscript 3 Baseline + Upper C l Subscript 2 Baseline right arrow Upper P Upper C l Subscript 5.
What is the mole ratio of PCl3 to PCl5?
Answer: The mole ratio of [tex]PCl_3[/tex] to [tex]PCl_5[/tex] is 1: 1
Explanation:
According to the balanced chemical equation ,the number of atoms of each element has to be same on reactant and product side. The stoichiometric coefficients of the species represent their number of moles.
[tex]PCl_3+Cl_2\rightarrow PCl_5[/tex]
Thus in the reactants, there is 1 mole of [tex]PCl_3[/tex] and 1 mole of [tex]Cl_2[/tex] molecule. And thus there is 1 mole of [tex]PCl_5[/tex] in the product as well.
Thus the mole ratio of [tex]PCl_3[/tex] to [tex]PCl_5[/tex] is 1: 1
What does chemical weathering do to the original minerals (THIS IS SCIENCE BUT I COULDN'T FIND SCIENCE CATAGOREY)
Answer:
Chemical weathering changes the composition of the original minerals.
Explanation:
Which statement best describes the particles in a sample of H2O in the solid phase?Immersive Reader
(10 Points)
They move very quickly and rarely interact.
They move very quickly and frequently collide.
They vibrate in place and have very weak bonds.
They vibrate in place and have very strong bonds.
Answer:
You can describe, the state, the color, the texture, and the odor of matter using your senses. ... As the motion of particles continues to increase, they move even farther apart. ... For example water is normally a liquid at room temperature. When it ... Gases have the most kinetic energy because their particles move very quickly.
Explanation:
Hopefully this helps!
Answer:
They vibrate in place and have very strong bonds.
Explanation:
All solids, in their form, have particles that vibrate in place and strong bonds to keep their form.
Choose the balanced chemical equation below that best represents the following reaction:
When baking soda (NaHCO3) reacts with hydrochloric acid (HCl), carbon dioxide bubbles (CO2) are created, along with water (H2O) and sodium chloride (NaCl).
NaCl + H2O → NaHCO3 +CO2 + HCl
CO2 +H2O + NaCl → NaHCO3 + HCl
NaHCO3 + HCl → CO2 + H2O + NaCl
HCl + NaCl + H2O → NaHCO3 +CO2
The balanced chemical equation :
NaHCO₃ + HCl → CO₂ + H₂O + NaCl
Further explanationA balanced chemical reaction shows that the number of atoms of the reactant and the number of atoms of the product is the same
When baking soda (NaHCO3) reacts with hydrochloric acid (HCl), carbon dioxide bubbles (CO2) are created, along with water (H2O) and sodium chloride (NaCl) .
This statement shows that
Reactants (located to the left of the reaction)
Baking soda (NaHCO₃) and Hydrochloric acid (HCl)
product (located to the right of the reaction)
Carbon dioxide(CO₂),water (H₂O) and Sodium chloride (NaCl).
So the reaction :
NaHCO₃ + HCl → CO₂ + H₂O + NaCl
The specific heat of a substance which absorbs 7.5 x 10^3 J of
heat when a sample with a mass of 1.0 x 10^5g of the
substance increases in temperature from 10°C to 90° C will
be:
Answer:
9.4 x 10^-4 J/g°C
Pleaseeesseeeeesssseredseeeesss
Answer:
B. Electrons travel through the sol
Explanation:
thats your answer :)
When energy is changed from one form to another, _____.
all of the energy is changed to a useful form
a physical change occurs
all of the energy can be accounted for
some of the energy is lost entirely
Answer:
some of the energy is lost entirely
Explanation:
which of the following is an oxyanion?
Answer:
please give the answer choice.