So, Ecosystem Diversity is a term that describes how different habitats of organisms are. For example, the fact that our planet has deserts, tundras but also estuaries is a sign of the diversity of its ecosystems. Species diversity refers to the number of different species that inhabit a specific ecosystem or the whole biosphere; the more, the better for species diversity. Genetic diversity is the term we are looking for; it means the variation in genes (usually in one species) that leads to different inheritable traits (in members of the same species). For example eye color is an inheritable trait that showcases genetic diversity since there are many genes that determine a different color such as brown, blue, green etc. (even though the environment plays a role too). Finally, natural selection is a theory about the survival of the fittest due to competition. It relates to inheritable traits and their diversity but it does not describe them.
Why is it important to know gas properties at STP?
Answer:
STP values are most often cited for gases because their characteristics change dramatically with temperature and pressure. One common definition of STP is a temperature of 273 K (0° Celsius or 32° Fahrenheit) and the standard pressure of 1 atm. Under these conditions, one mole of a gas occupies 22.4 L.
From where do the placenta and umbilical cord develop?
Answer:
it develops from the womb
Answer:
outer cells of the blastocyst
Explanation:
on edg:)
What is the energy of an electron in the third energy level of hydrogen?
Answer:
Electrons in a hydrogen atom must be in one of the allowed energy levels. If an electron is in the first energy level, it must have exactly -13.6 eV of energy.
...
Energy Levels of Electrons.
Energy Level Energy
1 -13.6 eV
2 -3.4 eV
3 -1.51 eV
4 -.85 eV
A hypothetical element X is found to have an atomic mass of 37.45 amu. Element X has only two isotopes, X-37 and X-38. The X-37 isotope has a fractional abundance of 0.7721 and an isotopic mass of 37.24. What is the isotopic mass of the other isotope?
Answer: The isotopic mass of the other isotope is 38.16 amu
Explanation:
Mass of isotope X-37 = 37.24
fractional abundance of isotope X-37 = 0.7721
Mass of isotope X-38 = ?
fractional abundance of isotope X-38 = (1-0.7721)= 0.2279
Formula used for average atomic mass of an element :
[tex]\text{ Average atomic mass of an element}=\sum(\text{atomic mass of an isotopes}\times {{\text { fractional abundance}})[/tex]
[tex]37.45=\sum[(37.24\times 0.7721)+(x\times 0.2279)][/tex]
[tex]x=38.16[/tex]
Therefore, the isotopic mass of the other isotope is 38.16 amu
Racecar driver Keimesha was in a race and accelerated from rest to 39 m/s by the time she reached the finish line. Keimesha’s car moved in a straight line and traveled from the starting line to the finish line in 6.0 seconds. What was the acceleration of the dragster?
Answer:
the acceleration of the racecar is 6.5 m/s²
Explanation:
Given;
initial velocity of the racecar, u = 0
final velocity of the racecar, v = 39 m/s
time of motion, t = 6.0 s
The acceleration of the racecar is calculated as;
[tex]a = \frac{v-u}{t} \\\\a = \frac{39-0}{6} \\\\a = \frac{39}{6} \\\\a = 6.5 \ m/s^2[/tex]
Therefore, the acceleration of the racecar is 6.5 m/s²
Please answer this. List the three most abundant minerals in this bottle of mineral water.
If an object gets smaller due to a change in state, what happens to its volume? How will this affect its density?
Answer:
the volume of a object will go down but the density stays the same
I haven’t shifted before I tried like once a few months ago and I keep wanting to shift and last night I had a dream I did is that a sign? I mean where I shifted it was to my friend in Australia so not Hogwarts or Marvel
The formation of tert-butanol is described by the following chemical equation: Suppose a two-step mechanism is proposed for this reaction, beginning with this elementary reaction: Suppose also that the second step of the mechanism should be bimolecular. Suggest a reasonable second step. That is, write the balanced chemical equation of a bimolecular elementary reaction that would complete the proposed mechanism.
Answer:
(CH3)3C^+ + OH^- --------> (CH3)3COH
Explanation:
This reaction has to do with SN1 reaction of alkyl halides. Here tert-butanol is formed from tert-butyl bromide.
The first step in the reaction is the formation of a carbocation. This is a unimolecular reaction. The rate of reaction depends on the concentration of the alkyl halide. This is a slow step and thus the rate determining step in the mechanism.
(CH3)3CBr -------> (CH3)3C^+ + Br^-
The second step is a fast step and it completes the reaction mechanism. It is a bimolecular reaction as follows;
(CH3)3C^+ + OH^- --------> (CH3)3COH
Over an interval of 2.0 s the average rate of change of the concentration of C was measured to be 0.0540 M/s. What is the final concentration of A at the end of this same interval if its concentration was initially 2.000 M
Answer:
Explanation:
the average rate of change of the concentration =
( initial concentration - final concentration ) / time
Initial concentration = 2.000 M
the average rate of change of the concentration = .0540 M/s
time = 2 s
Putting the values
.0540 = (2.000 - X ) / 2
0.108 = 2.000 - X
X = 1.892 M .
Final concentration = 1.892 M .
After adding 20.0 mL of 5% NaOH solution into the remaining organic layer, followed by mixing and venting, the solution separated into two distinct layers. Match the following:
1. The top layer was the ______________ layer.
2. 9-fluorenone was most soluble in the ____________ layer.
3. Deprotonated chloroanilic acid was most soluble in the _____________ layer.
4. The bottom layer was the __________________ layer.
5. The organic layer was a ________________ colored solution.
6. The aqueous layer turned into a _____________ colored solution.
a. organic
b. aqueous
c. yellow
d. pink
Answer:
Explanation:
The objective of this experiment is to match the expected result with each of the propositions given after the experiment had been carried out.
1. The top layer was the organic layer. This is because all the organic compounds have lesser density than water except chloroform that will be formed when NaOH is added.
2. 9-fluorenone was most soluble in the organic layer. This is so as a result of its non-polar carbon structure.
3. Deprotonated chloroanilic acid was most soluble in the aqueous layer as a result of the formation of an electrovalent bond with water.
4. The bottom layer was the aqueous layer as a result of the huge amount of water density.
5. The organic layer was a yellow colored solution.
6. The aqueous layer turned into a pink colored solution.
if a gas at 300k occupies 3.60 liters at a pressure of 1.00 atm, what will be it’s new pressure if the volume is compressed to 2.0 liters at a temperature of 450K?
Answer: The new pressure if the volume is compressed to 2.0 liters at a temperature of 450K is 2.7 atm
Explanation:
The combined gas equation is,
[tex]\frac{P_1V_1}{T_1}=\frac{P_2V_2}{T_2}[/tex]
where,
[tex]P_1[/tex] = initial pressure of gas = 1.00 atm
[tex]P_2[/tex] = final pressure of gas = ?
[tex]V_1[/tex] = initial volume of gas = 3.60 L
[tex]V_2[/tex] = final volume of gas = 2.0 L
[tex]T_1[/tex] = initial temperature of gas = [tex]300K[/tex]
[tex]T_2[/tex] = final temperature of gas = [tex]450K[/tex]
Now put all the given values in the above equation, we get:
[tex]\frac{1.00\times 3.60}{300}=\frac{P_2\times 2.0}{450}[/tex]
[tex]P_2=2.7atm[/tex]
The new pressure is 2.7 atm
According to the Bohr model of the atom, which particles are allowed to exist in any one of a number of energy levels?
Answer: the line-emission spectrum of an atom is caused by the energies released when electrons. releases energy of only certain values.
Which of the following substances contains MOSTLY ionic bonding? A) LIF B) CO2 C) AICI: D) BeCl2 E) Cu
Answer: [tex]LiF[/tex] , [tex]AlCl_3[/tex] and [tex]BeCl_2[/tex]
Explanation:
An ionic bond is formed when an element completely transfers its valence electron to another element. The element which donates the electron is known as electropositive element or the metal and the element which accepts the electrons is known as electronegative element or non metal.
A covalent bond is formed when an element shares its valence electron with another element. This bond is formed between two non metals.
[tex]LiF[/tex] , [tex]AlCl_3[/tex] and [tex]BeCl_2[/tex] contain ionic bonds as they aremade up of metals and non metals.
A sample consisting of 65.0 g of xenon is confined in a container at 2.00 atm and 298 K and then allowed to expand adiabatically (a) reversibly to 1.00 atm, (b) against a constant pressure of 1.00 atm. Calculate the final temperature and the expansion work at each case. Use the fact that xenon is a monoatomic gas.
Answer:
[a]. - 445.45J,
[b]. - 367.92 J
Explanation:
The following parameters are given in the question above. These information are used in solving this problem.
The mass of Xenon = 65.0 g of xenon, pressure = 2.00 atm, temperature = 298 K.
The number of moles of xenon = mass/ molar mass = 65g/ 131.293= 0.495.
The cp= 3/2 R, cp =3/2R + R = 5/2 R.
j = cp/cv = 3/2.
[a]. The final temperature,T2 = (2)^-2/3 × (298)^5/3 = T2^5/3.
Final temperature,T2 = 225.84K.
Expansion work = nCv [ T₂ - T₁] = 0.495 × 3/2 × 8.314 × [ 225.84 - 298] = - 445.45J.
(b). The final temperature can be Determine as;
3/2( T2 - 298k) = - 1 (T2 /1 - 298/2).
3/2(T2 - 298) = - T2 + 149K.
3T2 - 894 = - 2T2 +298K.
T2 = 238.4 K.
Workdone= nCv (T2 - T1) = 0.495 × 3/2 × 8.314 (238.4 - 298) = - 367.92 J.
How many molecules in 4.10 mol H2O?
6.02×10^23
1.4×10^23
2.47×10^24
1.15×10^-23
Answer:
2,47 * [tex]10^{24}[/tex] (molecules)
Explanation:
Avogadro's number is a very important relationship: 1 mole = 6,02 * [tex]10^{23}[/tex] atoms, molecules, protons, etc.
To convert from moles to molecules, multiply the molar amount by Avogadro's number.
4,1 mol * 6,02 * [tex]10^{23}[/tex] ≈ 24,7 * [tex]10^{23}[/tex] = 2,47 * [tex]10^{24}[/tex] (molecules)
Therefore the third answer is correct
After two half-lives, how much of the original material has decayed? 25 percent 50 percent 75 percent 100 percent
The original material has decayed 75%
Further explanationGiven
two half-life
Required
The decayed sample
Solution
General formulas used in decay:
[tex]\large{\boxed{\bold{N_t=N_0(\dfrac{1}{2})^{t/t\frac{1}{2} }}}[/tex]
t = duration of decay
t 1/2 = half-life
N₀ = the number of initial radioactive atoms
Nt = the number of radioactive atoms left after decaying during T time
t = 2 x t 1/2
Input the value :
[tex]\tt \dfrac{Nt}{No}=\dfrac{1}{2}^2=\dfrac{1}{4}=25\%[/tex]
The amount of Nt = 25% No
f) How many neutrons are there in the nucleus of arsenic?
1. Neodymium
2. Selenium
3. Strontium
Explanation:
How many neutrons are there in the nucleus of arsenic?42 neutrons
The nucleus consists of 33 protons (red) and 42 neutrons (blue).
In which state of matter are the particles at rest (not moving at all)?
none of these
solid
liquid
gas
Answer:
Solids for sure
particles of solid cant flow.
Answer:
B)Solids
Solids have tightly packed particles unlike liquids and gases whose particles can move freely but rate of movement is highest in gas while compared to water
Calculate the kinetic energy of an electron ejected from a piece of sodium (Φ = 4.41x10–19 J) that is illuminated with 265 nm light.
in Joules
Answer:
Explanation:
Energy of falling radiation having wavelength of 265 nm
= h c / λ where h is plank's constant , c is velocity of light and λ is wavelength of radiation . Putting the values
Energy of light photon = 6.6 x 10⁻³⁴ x 3 x 10⁸ / 265 x 10⁻⁹
= .0747 x 10⁻¹⁷
= 7.47 x 10⁻¹⁹ J .
Work function of sodium is 4.41 x 10⁻¹⁹
So kinetic energy of ejected electron = energy of falling photon - work function
= 7.47 x 10⁻¹⁹ - 4.41 x 10⁻¹⁹
= 3.06 x 10⁻¹⁹ eV .
How is a magnetic field produced?
O when an electromagnetic field interacts with a magnet
O when a current runs through a conductor
O when an object has an electric charge
O when electrons move through a circuit
Answer:
A magnetic field is a vector field that describes the magnetic influence on moving electric charges, electric currents, and magnetic materials. ... Magnetic fields are produced by moving electric charges and the intrinsic magnetic moments of elementary particles associated with a fundamental quantum property, their spin.
Answer: when an electromagnetic field interacts with a magnet
Explanation:
A speed boat, at full throttle, can go 65.0 miles in 1.5 hours. What is the average speed of the boat?
The average speed = 43.33 miles per hours(mph)
Further explanationGiven
distance = 65 miles
time = 1.5 hours
Required
The average speed
Solution
The average speed : distance traveled divided by time taken or total distance divided by total elapsed time
Can be formulated :
avg speed = distance : time
avg speed = d : t
Input the value :
avg speed = 65 miles : 1,5 hours
avg speed = 43.33 miles per hours(mph)
please help me with this problem
the amount of reactants = the amount of products
N2 + 3H2 --> 2NH3
When an oxidant is present, vitamin C can be converted to a product described as (5R)-5-[(1S)-1,2-dihydroxyethyl]-3,4-dihydroxy-furan-2,3,4(5H)-trione, which retains the furan-based nomenclature of vitamin C and describes the hydrogen placement at atom 5 of the ring. Which of the following statements best describes this vitamin C derivative?A) Vitamin C is reduced to yield a furan ring with 4 carbonyl groups and no double bonds.B) Vitamin C is oxidized to yield a furan ring with 3 carbonyl groups and 1 double bond.C) Vitamin C is reduced to yield a furan ring with 1 carbonyl group and no double bonds.D) Vitamin C is oxidized to yield a furan ring with 3 carbonyl groups and no double bonds
Answer:
D) Vitamin C is oxidized to yield a furan ring with 3 carbonyl groups and no double bonds
Explanation:
We can tell that the compound " (5R)-5-[(1S)-1,2-dihydroxyethyl]-3,4-dihydroxy-furan-2,3,4(5H)-trione " has 3 carbonyl groups due to it having "trione" in the name (and it lacking other carbonyl group names, like amide or carboxylic acid).
As there is no "-ene" part of the name referencing a double bond, the only option left is option D).
Consider an experimental setup with two compartments separated by a phospholipid bilayer membrane containing ion channels selectively permeable only to chloride ions. The left compartment (also called inside) contains 1 mM Cl- and the right compartment (also called outside) contains 100 mM Cl-. What will the electrical potential be when the system attains equilibrium
This question is incomplete, the complete question is;
Consider an experimental setup with two compartments separated by a phospholipid bilayer membrane containing ion channels selectively permeable only to chloride ions. The left compartment (also called inside) contains 1 mM Cl- and the right compartment (also called outside) contains 100 mM Cl-. What will the electrical potential be when the system attains equilibrium? [ assume body temperature; log 100 = 2, log 10 = 1, log 1 = 0, log 0.1 = -1, log 0.01 = -2]
Options;
a) -62 mV
b) -124 mV
c) +62 mV
d) 0 mV
e) +124 mV
Answer:
the electrical potential be when the system attains equilibrium is –124mV
Option b) –124mV is the correct answer
Explanation:
Given the data in the question;
Two compartments are divided by lipid bilayer;
In inside compartment Cl- ion concentration- 1mM and out side of the cell concentration is 100mM
now we apply the Nernst equilibrium potential equation;
Chlorine ion valency is z = –1
So
[tex]E_{eq}[/tex] = 62/z × log(ion outside/ ion inside) [for Cl‐ ions]
[tex]E_{eq}[/tex] = (62 / –1) x log( 100 / 1 )
[tex]E_{eq}[/tex] = -62 x 2 =
[tex]E_{eq}[/tex] = –124mV
Therefore, the electrical potential be when the system attains equilibrium is –124mV
Option b) –124mV is the correct answer
What is the definition of lava?
Answer:
Lava, magma (molten rock) emerging as a liquid onto Earth's surface. The term lava is also used for the solidified rock formed by the cooling of a molten lava flow.
Explanation:
What is the percent oxygen in Rb2Cr2O7
Answer:
28.9452
Explanation:
Answer:
28.9452%
Explanation:
Rb-44.1781
Cr-26.8767
O-28.9452
cos(A)+cos(2A)+cos(3A)=0 is not an identity
Answer:
this is the required answer look it once
Observation of balloon rub with cloth?
Answer:
When rubbing a balloon with a wool cloth, it puts negative charges on the balloon. Negative charges attract to positive charges. ... When both balloons are rubbed with the wool cloth, the both receive negative charges, so they will repel each other.
Why does heating increase the speed at which a solute dissolves in water?
O A. It decreases the surface area of the solute.
B. It prevents the solute from cristallizing.
O c. It makes the water molecules move faster.
D. It raises the pressure of the water molecules.
Answer: C
Explanation:
It gives kinetic energy to the molecules and it breaks the bonds faster because they jiggle more