Answer:
E. ^51 V
Atomic number (number of protons in the nucleus): 23
Atomic symbol (on the periodic table of the elements): V
Atomic weight (average mass of the atom): 50.9415
Density: grams per cubic centimeter
Phase at room temperature: Solid
Melting point: 3,470 degrees Fahrenheit (1,910 degrees Celsius)
Boiling point: 6,165 F (3,407 C)
Number of isotopes (atoms of the same element with a different number of neutrons): 2; one stable V-51; one radioactive V-50
Most common isotopes: V-51 (99.75 percent natural abundance)
Answer: Blocks harmful UV rays transports and distributes heat cycles essential elements: C, O, and N
Explanation:
The atmosphere is the integral part of the earth this typically includes gases which are necessary for sustaining lives on earth. The earth atmosphere forms a protective blanket around the inner earth which prevents the entry of majority of UV rays directly coming from the sun, This way atmosphere plays an important role in protecting the living beings from carcinogenic UV rays. It distributes the heat coming from the sunlight also it reflect back the absorb heat energy to the space acquired from the sun so as to maintain the balance of heat on planet earth.
It essentially plays an important role in circulation of essential gaseous elements like carbon, oxygen and nitrogen as these are required by the plants to conduct photosynthesis, respiration and protein synthesis respectively. Majorly all other life forms on earth are dependent on plants for food requirements therefore this cycling is beneficial for sustaining their lives too.
fusion
chemical
ionic
Answer: The correct answer is fusion reaction.
Explanation:
Nuclear fission reaction is defined as the reaction in which a heavier nuclei dissociates into two or more lighter nuclei.
Nuclear fusion reaction is defined as the reaction in which lighter nuclei combines to form a heavier nuclei.
Chemical reaction is defined as the reaction in which change in composition takes place. A new substance gets formed in this type of reaction.
The chemical equation for the formation of helium-4 atom follows:
In the above reaction, two hydrogen nuclei are combining together to form a heavier nuclei which is helium atom.
Thus, the correct answer is fusion reaction.
(2) They are Arrhenius acids and they turn red litmus blue.
(3) They are Arrhenius bases and they turn blue litmus red.
(4) They are Arrhenius bases and they turn red litmus blue.
Answer:The correct answer is option (1).
Explanation:
Arrehinius acid are those which gives hydronium ion when dissolved in water.
Arrehinius base are those which gives hydroxide ion when dissolved in water.
Both nitric acid and acetic acid are Arrhenius acids.And they turn the color of blue litmus paper to red color.
Hence, the correct answer is option (1).
B. The greater the dipole moment, the stronger the dipole-dipole forces.
C. The polarizability of elongated molecules is greater than that of compact, more spherical molecules.
D. London dispersion forces weaken in the order Xe < Kr < Ar
E. Hydrogen bonding leads to the strongest intermolecular forces.
Answer:
D. London dispersion forces weaken in the order Xe < Kr < Ar is an incorrect order, the correct order of London dispersion forces weaken in the order Ar < Kr < Xe.
Explanation:
A. Dispersion forces are present in all molecular substances.
is a correct statement London dispersion forces are weak intermolecular forces found in all molecular substances.
B. Clearly, greater the dipole moment, greater will be dipole-dipole forces. Hence true.
C) The polarizability of elongated molecules is greater than that of compact, more spherical molecules. The more elongated the molecule is more will be its ability to get polarized.
D. London dispersion forces weaken in the order Xe < Kr < Ar is an incorrect order, the correct order of London dispersion forces weaken in the order Ar< Kr < Xe.
E) Hydrogen bonding leads to the strongest intermolecular forces is also a correct statement. Hydrogen bonding leads to increase in boiling point.
Answer: ratio is 10⁻⁵
Explanation:
From Acid-dissociation equilibrium constant, HA is given thus,
HA + H₂O ⇄ H₃O⁺ + A⁻
equilibrium constant, Ka = [H₃O⁺] [A⁻] / [HA]
[H₃O⁺] = Ka [HA] / [A⁻]
from this we have that
pH = -log[H₃O⁺]
and pKa = -logKa
Applying Henderson-Hassel bach equation;
pH = pKa + log [A⁻]/[HA] ...........(1)
A⁻ rep the salt and HA rep the acid
at a given pH of 7, the pKa value of carboxylic acid COOH is 3
∴ from equation (1).
7 = 3 + log(COO⁻/COOH)
log(COO⁻/COOH) = 4
thus (COO⁻/COOH) = 10⁻⁴ ...................(2)
The ratio of alanine COOH to COO- at pH 7 is (COO⁻/COOH) = 10⁻⁴
(ii) Also considering the ratio of alanine NH2 to NH3+ at pH 7 we have;
given Pka value is 8,
therefore pH = pKa + log [salt]/[base]
7 = 8 + log (NH₂/NH₃)
(NH₂/NH₃) = 10⁻¹
thus the ratio of the concentration of the neutral amino acid species to the zwitterionic species at pH 7 is;
10⁻⁴ ˣ 10⁻¹ = 10⁻⁵
cheers i hope this helps