A stent is a small mesh tube that holds open passages in the body, such as weak or narrow arteries.
Explanation:
To open an artery near the heart
just took the quiz
Equal mases of ethane and hydrogen are mixed in an empty container at 25 degree celcius.The fraction of the total pressure exerted by hydrogen is
Answer:
15/16
Explanation:
We need to find the number of moles of hydrogen and number of moles of ethane present.
Since we have the same mass, m for both substances, the number of moles of hydrogen, n = m/M where M = molar mass of hydrogen molecule
Since hydrogen is H₂, M = 2 × 1 g/mol = 2 × 1 g/mol = 2 mol.
n = m/M
n = m/2
Also, number of moles of ethane, n' = m/M' where M' = molar mass of ethane.
Since ethane is C₂H₆, M' = 2 × 12 g/mol + 6 × 1 g/mol = 24 g/mol + 6 g/mol = 30 g/mol
n' = m/M'
n' = m/30
The total number of moles of gas present is thus n" = n + n' = m/2 + m/30 = (15m + m)/30 = 16m/30
The mole fraction of hydrogen is thus number of moles of hydrogen/total number of moles = n/n" = m/2 ÷ 16m/30 = m/2 × 30/16m = 15/16
Also, since the partial pressure due to hydrogen, P = mole fraction × total pressure, P'
P/P' = mole fraction = 15/16
So, The fraction of the total pressure exerted by hydrogen is 15/16
Select the correct answer.
A sample taken from a layer of mica in a canyon has 2.10 grams of potassium-40. A test reveals it to be 2.6 billion years old. How much
potassium-40 was in the sample originally if the half-life of potassium-40 is 1.3 billion years?
O A.
4.20 g
O B.
8.40 g
O C.
12.6 g
• D.
16.8 g
O E.
25.2 g
Answer:
8.36 g
Explanation:
From;
0.693/t1/2 = 2.303/t log (No/N)
t1/2 = half life of potassium-40
t = age of the sample
No= initial amount of the sample
N= amount of the sample at time t
Substituting values;
0.693/1.3 × 10^9 = 2.303/2.6 × 10^9 log (No/2.10)
5.33 × 10^-10 = 8.86 × 10^-10 log (No/2.10)
5.33 × 10^-10/8.86 × 10^-10 = log (No/2.10)
0.6 = log (No/2.10)
Antilog (0.6) = (No/2.10)
No = 2.10 × Antilog (0.6)
No= 8.36 g
1. The science that deals with heredity and the factors affecting the transmission of the characteristics is
2. The trait that is usually hidden and will just come out on the second generation is
3. The appearance of the offspring is referred to as
4. The genetic make-up of the genes of the offspring is
5. Having two identical alleles of a particular gene or genes is called
6. The father of Science of Genetic is
7. It is the trait that is being expressed in an organism.
8. The extent to which something is probable is
9. The offspring of two plants/animals of different species or varieties is called
10. It is the number of times that the genotype would appear in an offspring after a test cross is
11. The relative number of offspring manifesting a particular trait or a combination of traits.
12. Having two different alleles of a particular gene or genes is
Answer:
1-Genetics
2-Alleles
3-Organism's genotype
4-Phenotypes and Genotypes
5-Allele
6-Gregor Mendel
7-Genotype
8-Probability
9-Hybrid
10-Genotypic Ratio
11-Phenotypic ratio
12-Heterozygous
Explanation:
HCl + Fe?ra gì hihihihi
Answer:
fecl2+ h2
Explanation:
What type of reaction is shown below?
H202 + H2O + O2
Single replacement
Combustion
Synthesis
Decomposition
Answer:
Decomposition Reaction
The relative atomic mass of helium is 4 and the relative atomic mass of bromine is 80. How many helium atoms will be as one bromine atom?
Answer:
80÷4=20 Helium atoms
Explanation:
Because one helium atom is a quarter of of one bromine atom
Antara berikut ciri manakah bear tentang cuka?
A. Berasa pahit.
B. Berasa tawar.
C. Nilai pH kurang dari 7
D. Nilai pH ialah 7
Answer:
c. nilai pH kurang dari 7
Explanation:
cuka adalah acid
nilai pH bagi acid adalah
antara 1 hingga 6
in which of the following type of colloid, the physical state of dispersed phase and dispersion medium is same?
Gel
Foam
Emulsion
Aerosol
Answer:
Emulsion
Explanation:
According to Oxford dictionary, a colloid is, ''a homogeneous non-crystalline substance consisting of large molecules or ultramicroscopic particles of one substance dispersed through a second substance. Colloids include gels, sols, and emulsions; the particles do not settle, and cannot be separated out by ordinary filtering or centrifuging like those in a suspension.''
An emulsion is a dispersion of a liquid in a liquid. This means that the the physical state of dispersed phase and dispersion medium is same.
Examples of emulsions include; Vinaigrette, homogenized milk and hair cream.
Tertiary alkyl halides show SN1 reactions mostly...... Why?
Answer:
Generally SN1 reactions are carried out in polar protic solvents. The energy required for breaking the C-X bond is obtained through solvation of halide ion with the proton of the solvent. Tertiary alkyl halides undergo SN1 reaction very fast because of the high stability of tertiary carbocations.
Which best describes a mixture?
It has a single composition, and it has a set of characteristics that does not change.
O It can have different compositions, but it has a set of characteristics that does not change.
O It has a single composition, but it has a set of characteristics that does change.
It can have different compositions, and it has a set of characteristics that does change.
Mark this and return
Save and yit
Answer:
I think the answer would be b, sorry if I'm wrong(EDIT: ITS ACTUALLY AAAAA)
Which question would most likely be studied by a physicist?
A.
Were there ever any living organisms on Mars?
B.
Should the government spend taxpayers' money to send space probes to Mars?
C.
How can the forces on a space probe be controlled so it will land on Mars?
D.
What type of substances make up the soil on Mars?
Answer:
C.
Explanation:
Physicists main field of study is physics. This includes everything from force, matter, energy, and even time among other things. Therefore, from the questions provided the one that would most likely be studied by a physicist would be How can the forces on a space probe be controlled so it will land on Mars? This is because this question deals with forces acting on an object, regardless of what the object is Force is a huge part of physics and therefore studied by Physicists.
A cart accelerating slower when mass was increased.
1st Law - 3rd Law
Answer:
Newton's second law
Explanation:
It is mentioning acceleration and mass
Newton's second law's equation = F = m*a
Hope u understood
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Thank You
What is the perimeter of a polygon 8cm 6cm, 4cm, 6cm
Answer:
24cm
Explanation:
The perimeter of a polygon is obtained by the sum of the length of each side of the figure.
The polygon of the problem has four sides with the following measurements:
8cm, 6cm, 4cm and 6cm.
That means the perimeter of this shape is:
8cm + 6cm + 4cm + 6cm =
24cm200 ml of a LiF solution is 5.0M concentration. How many grams of LiF does it have?
Write the electronic configuration of calcium and potassium.
Answer:
Calcium= 2,8,8,2
Potassium= 2,8,8,1
Answer:
Electronic configuration of Potassium (K)Atomic number of potassium = 19
Therefore number of electrons = 19
Since, maximum number of electrons in outermost orbit will not be more than 8, thus the 19th electron of potassium atom will reside in 4th.
Thus, electronic configuration of potassium is
given in first pic.
Number of orbit in potassium = 4
Electronic configuration of Calcium (Ca)Atomic number of calcium = 20
Therefore number of electrons = 20
Thus, electronic configuration of calcium is given in sec pic.
Number of orbit in calcium = 4
Explanation:
❤️(◍ Jess bregoli ◍)❤#keep learning!!
When a substance melts, evaporates or boils, which four of the following things are true for it's particles?
Select four answers.
A. Lose energy
B. Gain energy
C. Move more
D. Move less
E. Become further apart
F. Become closer together
G. Overcome the attractive forces
H. The forces between them hold them more in place
Answer:
B, C, E, G
Explanation:
B - As particles are heated, they gain heat energy (or thermal energy, Q) from whatever the source may be.
C - Thermal energy particles gain is converted into kinetic, and the more KE/kinetic energy particles have, the more energy they have to move around.
E - When particles have more energy to move around more, they slide and move past each other and create more space; hence, they become further apart.
G - Eventually, particles will have enough energy and will move around so much that the attracting forces holding them together in the first place will be lesser than the particle's energy to break free and move from the attractive forces.
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0.18 g of a divalent metal was completely dissolved in 250 cc of acidsolution containing 4.9 g H2SO4 per liter. 50 cc of theresidual acid solution required 20 cc of N/10 alkali forcomplete neutralization. Calculate the atomic weight of metal.
goodnight Gucci chunk cubic DDF if f Ch BK
ionic bonds show which characteristics that arent seen in covalent bonds
5. Which choice best represents the relationship between wavelength and frequency?
when frequency decreases, wavelength decreases
there is no relationship
when frequency increases, wavelength increases
O when frequency decreases, wavelength increases
A se ion has a mass number of 77
and a charge of −2
. Determine the number of neutrons, protons, and electrons in this ion.
Answer:
1. Neutron number = 43
2. Proton number = 34
3. Electron number = 36
Explanation:
From the question given above, the following data were obtained:
Mass number = 77
Charge of ion = –2
1. Determination of the number of neutron.
Mass number of Se = 77
Atomic number = 34
Neutron number =?
NOTE: Atomic number = proton number
Mass number = Proton + Neutron
77 = 34 + Neutron
Collect like terms
77 – 34 = Neutron
Neutron number = 43
2. Determination of the proton number.
The atomic number of an element is simply defined as the number of protons in the atom of the element. Mathematically,
Atomic number = Proton number
Atomic number of Se = 34
Therefore, the proton number of Se²¯ is 34.
NOTE: The atomic number does not change be it atom, ion or molecule. It remains the same.
3. Determination of electron number.
Charge of ion = –2
Proton number = 34
Electron number =?
Proton – Electron = Charge
34 – Electron = –2
Rearrange
34 + 2 = Electron
36 = Electron
Electron number = 36
There are 43 neutrons, 34 protons, and 36 electrons in the given selenium ion with a (-2) charge.
Explanation:
Given:
A selenium ion with a mass number of 77 and a charge of (-2).
To find:
The number of neutrons, protons, and electrons in selenium ion
Solution:
Charge on the selenium ion = -2
The atomic number of selenium = 34
Number of protons = Atomic number
Number of protons in selenium atom = 34
Number of protons in selenium ion = 34
Number of electrons in selenium atom = 34
Number of electrons in selenium ion= 34+2 = 36
(anion is formed by gaining of electrons that is why adding two electrons )
The mass number of selenium = 77
Mass number = Number of protons + Number of neutrons
77 = 34 + Number of neutrons in selenium
Number of neutrons in selenium ion = 77 - 34 = 43
There are 43 neutrons, 34 protons, and 36 electrons in the given selenium ion with a (-2) charge.
Learn more about atoms and ions here:
brainly.com/question/18481428
brainly.com/question/1659592?referrer=searchResults
By referring to the particulate theory of mater, explain the following statement: Oxygen gas is very easy to compress when pressure is applied
By referring to the particulate theory of matter, explain the following statement: A solid lump of iron has a high density .
Answer:
See explanation
Explanation:
According to the particulate theory of matter, gas particles do not interact with each other. A gas is composed of isolated particles moving at high velocities and collide frequently with each other and the walls of the container.
Since the particles of a gas are mostly isolated, it is easy to compress the gas when pressure is applied thereby bringing the gas particles closer together.
On the other hand, in the solid state, the particles that compose matter are close together. These particles only vibrate about their mean positions due to strong intermolecular interaction between particles. The fact that the particles of the solid ion are so close together makes the solid iron lump to possess high density.
name the gas which is formed when coal is heated in the absense of air
Answer:
Coke
Explanation:
A solid fuel formed by heating coal in the absence of air is coke. Coke is black colored, tough porous substance. It is pure carbon.
what is the change of state from gas to liquid
Vapourization and condensation. the actual 1 shud be vapourization.
what type of chemical is manganese(IV) oxide
Answer:
catalyst
Explanation:
it alters the speed of reaction
2 A certain gas of 25 g at 25°c and 0.65 atm occupies a volume of 23.52L Determine the molecule mass of the gas.
Answer:
[tex]{ \bf{PV= \frac{m}{M} RT}} \\ \\ { \tt{(0.65 \times 23.52) = \frac{25}{M} \times 0.081 \times (25 + 273)}} \\ \\ M = 39.5 \: g[/tex]
Nombra cada uno de los siguientes hidrocarburos de acuerdo a las reglas de la IUPAC
Answer:
i) ciclobutano
ii) 3-etil-4-metil ciclopenteno
Explanation:
Toda la idea de la nomenclatura IUPAC es permitir que la estructura de la sustancia se derive de su nombre y viceversa.
La nomenclatura IUPAC es un sistema universalmente aceptado para nombrar compuestos químicos.
los nombres de los compuestos enumerados son;
i) ciclobutano
ii) 3-etil-4-metil ciclopenteno
Sodium is less reactive than potassium.
Answer:
Sodium atoms due to being smaller in size have high ionization energy and thus, it can't lose electrons easily and is more stable and less reactive. ... Hence, from this it is clear that sodium is less reactive than potassium.
Explanation:
If oxygen has 6 valence electrons how many it would like to gain to have full valence shell? And what charge will it give to oxygen ion?
Answer:
Gain 2, and become negatively charged
Explanation:
A full valence shell, thus stablilized, has 8 electrons, and so it would need two more, and when atoms gain electrons, they become negatively charged because there are now more electrons than protons (and so, when they lose electrons, they become positively charged). Hope this helps! :)
PLEASE ANYONE HELP!!!
How does an increase in -CH2 groups in an organic chain affect the boiling point?
A. The boiling point increases as more -CH2 groups are added.
B. The boiling point increases up to 4 CH2 groups and then begins to decrease.
C. The boiling point is not affected by -CH2 groups, only by functional groups.
D. The boiling point decreases as more -CH2 groups are added.
Answer:
I believe it's a.
Explanation:
what are the difference between ionic bond and covalent bond?
Which is stronger?
QUËSTIONS :- what are the difference between ionic bond and covalent bond?
IONIC BONDS :- THEY R BONDS WHICH R FORMED DUE TO THE COMPLETE TRANSFER OF ELECTRONS BETWEEN TWO ATOMS
COVALENT BONDS :- THEY R THE BONDS WHICH R FORMED DUE TO INCOMPLETE TRANSFER OF ELECTRONS BETWEEN TWO ATOMS
IONIC BONDS R MORE STRONGER.
Explanation:
Ionic bond is much stronger than covalent bond because it involves complete transfer of electrons because of which there is formation of cation and anion and there exist huge electrostatic forces of attraction. They also have high melting and boiling point which proves that the ionic bond is very strong.
Differences between ionic bond and covalent bond :
Ionic Bonds. Covalent Bonds
Polarity :High. Low
Shape : No definite shape. Definite shape
Melting Point :High Low
Boiling Point: High Low
