1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
saul85 [17]
3 years ago
13

1. In addition to being necessary for respiration, _______ also provides UV radiation protection.

Chemistry
1 answer:
Harlamova29_29 [7]3 years ago
7 0
Oxygen - is the answer
You might be interested in
A concentration cell consisting of two hydrogen electrodes (PH2 = 1 atm), where the cathode is a standard hydrogen electrode and
Lunna [17]

The pH of the unknown solution is 3.07.

<u>Explanation:</u>

<u>1.Find the cell potential as a function of pH</u>

From the Nernst Equation:

Ecell=E∘cell−RT /zF × lnQ

where

R denotes the Universal Gas Constant

T denotes the temperature

z denotes the moles of electrons transferred per mole of hydrogen

F denotes the Faraday constant

Q denotes the reaction quotient

Substitute the values,

E∘cell=0   lnQ=2.303logQ

E0cell=−2.30/RT /zF × log Q

Solving the equation,

<u>2. Find the Q  value</u>

Q=[H+]2prod pH₂, product/ [H+]2reactpH₂, reactant

Q=[H+]^2×1/1×1=[H+]2

Taking the log

logQ= log[H+]^2=2log[H+]=-2pH

From the formula,

Ecell=−2.303RT /zF× logQ

E cell= 2.303 × 8.314 CK mol (inverse)  × 298.15

K × 2pH /2×96 485  C⋅mol

( inverse)

E cell= 0.0592 V × pH

<u>3. Finding the pH value</u>

E cell= 0.0592 V × pH

pH = E cell/ 0.0592 V= 0.182V/ 0.0592V

pH=3.07

The pH of the unknown solution is 3.07.

7 0
3 years ago
Which of the following describes a scenario in which the molecular geometry would have the smallest bond angle(s)? (A) four bond
maw [93]

Answer: The correct answer is "B" two bonding domains(or bonding pairs) or two non bonding domains(or lone pairs)

Explanation:

Molecular geometry/structure is a three dimensional shape of a molecule. It is basically an arrangement of atoms in a molecule.It is determined by the central atom, its surrounding atoms and electron pairs.According to VSEPR theory, there are 5 basic shapes of a molecule: linear, trigonal planar, tetrahedral, trigonal bipyramidal and octahedral.

A)Four bonding domains and zero non bonding domains: shape is tetrahedral and bond angle is 109.5°

B)Two bonding domains and two non bonding domains(lone pairs): shape is bent and bond angle is 104.5°

C)Three bonding domains and one non bonding domain: shape is trigonal pyramidal and bond angle is 107°

D)Two bonding domain and zero non bonding domain: shape is linear and bond angle is 107°

E)Two bonding domain and one non bonding domain: bent shape and bond angle is 120°

F)Three bonding domains and zero nonbonding domain: shape is trigonal planar and bond angle is 120°

Hence Two bonding domains and two non bonding domains have the smallest bond angle.

6 0
3 years ago
If the density of an object is 5 g/cm3 and it takes up 7 cm3 of space, calculate the mass?
statuscvo [17]

Answer:

<h2>The answer is option A</h2>

Explanation:

The mass of a substance when given the density and volume can be found by using the formula

<h3>mass = Density × volume</h3>

From the question

volume of object = 7 cm³

density = 5 g/cm³

The mass of the object is

mass = 5 × 7

We have the final answer as

<h2>35 g</h2>

Hope this helps you

8 0
3 years ago
According to the Bohr model of an atom, what happens when an electron moves from the second energy level to the third energy lev
kati45 [8]
<span>Energy is absorbed and then released to form an emission line.

When electrons absorb energy they increase there energy level. This is only temporary and the excited electron then relaxes back down to its original energy level releasing energy.

The energy is released in form of EM radiation of a specific frequency depending on the element and how many energy levels the electron relaxes. 
This forms an emission line.</span><span />
4 0
3 years ago
Read 2 more answers
What is the difference between unconfined aquifers and confined aquifers?
Marta_Voda [28]

Answer:

A

Explanation:

Unconfined aquifers are those into which water seeps from the ground surface directly above the aquifer. Confined aquifers are those in which an impermeable dirt/rock layer exists that prevents water from seeping into the aquifer from the ground surface located directly above.

5 0
3 years ago
Other questions:
  • A reaction that occurs when the reactants are simply put together is
    12·2 answers
  • How do you calculate the number of valence electrons in an atom?
    8·1 answer
  • How does a catalyst work
    5·2 answers
  • g How many grams of beryllium are needed to produce "11.5" g of hydrogen gas?Be(s) + 2H 2 O(l) → Be(OH) 2 (aq) + H 2 (g)
    5·1 answer
  • Are properties such as odor, color, density, and solubility physical or chemical properties?
    9·2 answers
  • . What is the first element on the periodic table?
    15·1 answer
  • Anyone could help me out?
    6·2 answers
  • PLEASE HELP THIS IS DUE TODAY
    11·1 answer
  • Help asap please. Will mark as the brainliest... NO LINKS!!!
    10·1 answer
  • How much energy is required to convert 100.0 g of water completely<br> to steam?
    11·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!