Answer:
[tex]\lambda =4.33x10^{-12}m=4.33pm[/tex]
Explanation:
Hello there!
In this case, since the speed, wavelength and mass of an electron are related via the the Broglie wavelength:
[tex]\lambda =\frac{h}{m*v}[/tex]
Thus, by plugging in the mass of the electron and the Planck's constant, we obtain the following wavelength:
[tex]\lambda =\frac{6.626x10^{-34}J*s}{9.11x10^{-31}kg*1.68x10^{8}m/s}\\\\\lambda =4.33x10^{-12}m=4.33pm[/tex]
Best regards!
For each of these pairs of half-reactions, write the balanced equation for the overall cell reaction and calculate the standard cell potential. Express the reaction using cell notation. You may wish to refer to Chapter 20 to review writing and balancing redox equations.
1.
Pt2+(aq)+2e-Pt(s)
Sn2+(aq)+2e-Sn(s)
2.
Co2+(aq)+2e-Co(s)
Cr3+(aq)+3e-Cr (s)
3.
Hg2+(aq)+2e-Hg (I)
Cr2+(aq)+2e-Cr (s)
please help out
1. For the pair of half-reactions:
Pt2+(aq) + 2e- → Pt(s) ... (1)
Sn2+(aq) + 2e- → Sn(s) ... (2)
To obtain the balanced equation for the overall cell reaction, we need to multiply the half-reactions by appropriate coefficients to ensure that the number of electrons transferred is equal. In this case, we can multiply equation (1) by 2 and equation (2) by 1:
2(Pt2+(aq) + 2e-) → 2(Pt(s))
Sn2+(aq) + 2e- → Sn(s)
Combining the equations, we have:
2Pt2+(aq) + Sn2+(aq) → 2Pt(s) + Sn(s)
The cell notation for this reaction is:
Pt2+(aq) | Pt(s) || Sn2+(aq) | Sn(s)
To calculate the standard cell potential (E°), we need to know the standard reduction potentials for Pt2+/Pt(s) and Sn2+/Sn(s) half-reactions. Referring to standard reduction potential tables, we find:
E°(Pt2+/Pt(s)) = +1.20 V
E°(Sn2+/Sn(s)) = -0.14 V
The overall cell potential (E°cell) is the difference between the reduction potentials:
E°cell = E°(cathode) - E°(anode) = 0.00 V - (-0.14 V) = +0.14 V
Therefore, the standard cell potential for this reaction is +0.14 V.
2. For the pair of half-reactions:
Co2+(aq) + 2e- → Co(s) ... (3)
Cr3+(aq) + 3e- → Cr(s) ... (4)
To balance the number of electrons transferred, equation (4) can be multiplied by 2:
2(Co2+(aq) + 2e-) → 2(Co(s))
Cr3+(aq) + 3e- → Cr(s)
Combining the equations, we have:
2Co2+(aq) + Cr3+(aq) → 2Co(s) + Cr(s)
The cell notation for this reaction is:
Co2+(aq) | Co(s) || Cr3+(aq) | Cr(s)
To calculate the standard cell potential (E°), we refer to the standard reduction potentials:
E°(Co2+/Co(s)) = -0.28 V
E°(Cr3+/Cr(s)) = -0.74 V
The overall cell potential (E°cell) is the difference between the reduction potentials:
E°cell = E°(cathode) - E°(anode) = -0.74 V - (-0.28 V) = -0.46 V
Therefore, the standard cell potential for this reaction is -0.46 V.
3. For the pair of half-reactions:
Hg2+(aq) + 2e- → Hg (l) ... (5)
Cr2+(aq) + 2e- → Cr(s) ... (6)
The equation for the overall cell reaction can be obtained by multiplying equation (6) by 2:
2(Hg2+(aq) + 2e-) → 2(Hg (l))
Cr2+(aq) + 2e- → Cr(s)
Combining the equations, we have:
2Hg2+(aq) + Cr2+(aq) → 2Hg (l) + Cr(s)
For more such questions on balanced equation.
https://brainly.com/question/11904811
#SPJ8
How many grams are in 3.5 moles of H2O?
Answer:
Hi
Explanation:
We assume you are converting between moles H2O and gram. You can view more details on each measurement unit: molecular weight of H2O or grams This compound is also known as Water or Dihydrogen Monoxide. The SI base unit for amount of substance is the mole. 1 mole is equal to 1 moles H2O, or 18.01528 grams.
1 mole is equal to 6.023 × 10 ²³ molecules. 63 grams are in 3.5 moles of H2O.
What do you mean by mole ?The term mole is defined as the amount of substance of a system which contains as many elementary entities.
One mole of any substance is equal to 6.023 × 10²³ units of that substance such as atoms, molecules, or ions. The number 6.023 × 10²³ is called as Avogadro's number or Avogadro's constant.
The mole concept can be used to convert between mass and number of particles.
We expect you are converting between moles H2O and gram. The molecular weight of H2O or gram's This compound is also known as Water or Dihydrogen Monoxide. The SI base unit for amount of substance is the mole. 1 mole is equal to 1 moles H2O, or 18.01528 grams.
Thus, 63 grams are in 3.5 moles of H2O.
To learn more about the mole, follow the link;
https://brainly.com/question/26416088
#SPJ2
It took 14.50 mL of 0.455M NaOH to fully neutralize 12.0mL of HCl. What is the concentration of the HCl?
HCl + NaOH \rightarrow→ NaCl + H2O
Answer:
0.550 M HCl
Explanation:
M1V1 = M2V2
M1 = 0.455 M NaOH
V1 = 14.50 mL NaOH
M2 = ?
V2 = 12.0 mL HCl
Solve for M2 --> M2 = M1V1/V2
M2 = (0.455 M)(14.50 mL) / (12.0 mL) = 0.550 M HCl
Answer:
The appropriate answer is "0.549 M".
Explanation:
The given values are:
N₁ = 14.50 mL
V₁ = 0.455 M
N₂ = 12 mL
Let
V₂ = C = ?
As we know,
⇒ [tex]N_1\times V_1=N_2\times V_2[/tex]
On substituting the values, we get
⇒ [tex]14.50\times 0.455 = 12\times C[/tex]
⇒ [tex]6.5975=12\times C[/tex]
⇒ [tex]C=\frac{6.5975}{12}[/tex]
⇒ [tex]=0.549 \ M[/tex]
Which layer of the Earth includes the crust? a atmosphere b hydrosphere c asthenosphere d lithosphere
Answer:
D
Explanation:
Hope that helps :)
Mixtures that would be considered buffers include which of the following? I. 0.10 M HCl + 0.10 M NaCl II. 0.10 M HF + 0.10 M NaF III. 0.10 M HBr + 0.10 M NaBr
Answer:
II. 0.10 M HF + 0.10 M NaF.
Explanation:
A buffer system may be formed in one of two ways:
A weak acid and its conjugate base.A weak base and its conjugate acid.Which of the following mixtures could be considered a buffer?
I. 0.10 M HCl + 0.10 M NaCl. No, because HCl is a strong acid.
II. 0.10 M HF + 0.10 M NaF. Yes, since HF is a weak acid and F⁻ (coming from NaF) is its conjugate base.
III. 0.10 M HBr + 0.10 M NaBr. No, because HBr is a strong acid.
A sample of chlorine gas has a volume of 0.30 L at 273 K and 1 atm pressure. What temperature (in ∘C) would be required to increase the volume to 1.0 L ?
Answer:
[tex]T_2=637\°C[/tex]
Explanation:
Hello there!
In this case, considering this problem as pressure constant, since the change is exhibited in temperature and volume only, it is possible for us to use the Charles' law as shown below:
[tex]\frac{V_2}{T_2}=\frac{V_1}{T_1}[/tex]
Thus, by solving for the final temperature, we obtain:
[tex]T_2=\frac{T_1V_2}{V_1}\\\\T_2=\frac{273K*1L}{0.30L}\\\\T_2=910K-273\\\\T_2=637\°C[/tex]
Best regards!
A solution contains 1.817 mg of CoSO4 (155.0 grams/mole) per mL. Calculate the volume (in mL) of 0.009795 M Zn2 needed to titrate the excess complexing reagent after the addition of 70.00 mL of 0.009005 M EDTA to a 20.00 mL aliquot of the Co2 solution.
Answer:
85.952 ml [tex]Zn^2^+[/tex] needed to titrate the excess complexing reagent .
Explanation:
Lets calculate
After addition of 80 ml of EDTA the solution becomes = 20 + 70 = 90 ml
As the number of moles of [tex]CoSO_4[/tex] =[tex]\frac{Given mass }{molar mass}[/tex]
=[tex]\frac{1.817}{155}[/tex]
=0.01172
Molarity = [tex]\frac{no. of moles}{volume of solution}[/tex]
=[tex]\frac{0.01172}{20}[/tex]
=0.000586 moles
Excess of EDTA = concentration of EDTA - concentration of CoSO4
= 0.009005 - 0.000586
= 0.008419 M
As M1V1 ( Excess of EDTA ) = M2V2 [tex](Zn^2^+)[/tex]
[tex]0.008419\times100ml=0.009795\times V2[/tex]
[tex]V2=\frac{0.008419\times100}{0.009795}[/tex]
V2 =85.952 ml
Therefore , 85.952 ml [tex]Zn^2^+[/tex] needed to titrate the excess complexing reagent .
Which of the following combinations of quantum numbers is permissible?Question 23 options: n = 1, l = 2, ml = 0, ms = n = 4, l = 3, ml = 1, ms = n = 3, l = 3, ml = 1, ms = n = 2, l = 1, ml = –1, ms = 0 n = 4, l = 3, ml = 4, ms =
Answer: n= 4, , l= 3, [tex]m_l[/tex] = 1, permissible
Explanation:
Principle Quantum Numbers : It describes the size of the orbital and the energy level. It is represented by n. Where, n = 1,2,3,4....
Azimuthal Quantum Number : It describes the shape of the orbital. It is represented as 'l'. The value of l ranges from 0 to (n-1).For l = 0,1,2,3... the orbitals are s, p, d, f...
Magnetic Quantum Number : It describes the orientation of the orbitals. It is represented as [tex]m_l[/tex]. The value of this quantum number ranges from [tex](-l\text{ to }+l).[/tex]
Spin Quantum number : It describes the direction of electron spin. This is represented as [tex]m_s[/tex]. The value of this is [tex]+\frac{1}{2}[/tex] for upward spin and [tex]-\frac{1}{2}[/tex] for downward spin.
a) n=1 , l= 2, [tex]m_l[/tex] = 0, not permissible as l can not greater than n.
b) n= 4, , l= 3, [tex]m_l[/tex] = 1, permissible
c) n= 3, l= 3, [tex]m_l[/tex] = 1, not permissible as l can not equal than n.
d) n= 4 , l= 3, [tex]m_l[/tex] = 4, not permissible as [tex]m_l[/tex] can not greater than l.
A change in velocity can occur without a change in speed *
A: True
B: False?
Answer: True
Explanation: For example, changing direction can change velocity
How many moles of hydrogen
are in 3.06 x 10^-3 g of glycine C2H5NO2
Answer:
2.04x10⁻⁴ mol
Explanation:
First we convert 3.06x10⁻³ grams of glycine into moles of glycine, using its molar mass:
3.06x10⁻³ g ÷ 75 g/mol = 4.08x10⁻⁵ mol C₂H₅NO₂In order to calculate the number of hydrogen moles, we multiply the number of glycine moles by 5, as there are 5 hydrogen moles per glycine mol:
4.08x10⁻⁵ mol C₂H₅NO₂ * 5 = 2.04x10⁻⁴ mol HThe elemental composition of propane gas (C3H8) is 81.68% C and 18.32% H by mass. What is the maximum amount of C3H8 in grams that can be formed from 160.0 g C and 160.0 g H
Molar mass of C3H8 = C 3 (12.01 g/mol) = 36.03 (g/mol)
H 8 (1.008 g/mol) = 8.064 (g/mol)
44.09 (g/mol)
74.6 g propane x 1 mole propane x 6.022 x 10
23
molecules
44.09 g propane 1 mole propane
= 1.02 x 10
24 molecules propane
Atoms in the same PERIOD have the same...
A. Number of energy levels
B. Size
C. Temperature
D. Reactivity
Answer:
A. Number of energy levels
how to calculate relative abundance of copper isotopes
Answer: Atomic mass (Cu) = (x)(63.0 amu) + (1 – x)(65.0 amu) = 63.5 amu 63.0x + 65 – 65.0x = 63.5 –2x = –1.5 x = 0.75 The percent abundance of each isotope is 75.0 % (Cu-63) and 25.0 % (Cu-65).
Explanation: As you know, the average atomic mass of an element is determined by taking the weighted average of the atomic masses of its naturally occurring isotopes.
Simply put, an element's naturally occurring isotopes will contribute to the average atomic mass of the element proportionally to their abundance.
4.00 g of O2 gas are in a sealed, 2.00 L gas canister at 22.0 °C what is the pressure inside this container (in atm)?
Answer:
1.51448 atms
Explanation:
List four reasons why the temperature of a flame is lower than the adiabatic flame temperature."
Answer:
substances is never entirely a one way
Explanation:
no possibility of obtaining complete combustion at hig
temperature.
always loss of heat from the temperature
its temperature is lower than the constant volume process because some of the energy is utilized to change the volume of the system
Four reasons why the temperature of flame is lower than adiabatic flame temperature is that there is no possibility of obtaining complete combustion at high temperature due to high thermal energy.There is always loss of heat from temperature,its temperature is lower than constant volume process because some of energy is utilized to change the volume of the system.
What is thermal energy?Thermal energy is defined as a type of energy which is contained within a system which is responsible for temperature rise.Heat is a type of thermal energy.It is concerned with the first law of thermodynamics.
Thermal energy arises from friction and drag.It includes the internal energy or enthalpy of a body of matter and radiation.It is related to internal energy and heat .It arises when a substance whose molecules or atoms are vibrating faster.
These vibrating molecules and atoms collide and as a result of which heat is generated in a substance , more the collision of particles , higher is the thermal energy.
Learn more about thermal energy,here:
https://brainly.com/question/18989562
#SPJ2
For any molecule at the surface the resulting surrounding forces equal zero
True
False
????????????????????????????????????????????????????,,
Assertion: The conversion of a gas directly into solid is called condensation. Reason : Naphthalene leaves no residue when kept in open for some time. *
The reason is not an explanation of the assertion as we can see, the concepts are not related.
What is condensation?The process by which a substance transforms from a gaseous state to a liquid state is known as condensation. When a gas's temperature is dropped, the gas molecules experience energy loss and coalesce to create a liquid.
The kinetic energy of gas molecules is transformed into potential energy during condensation when they slow down and move closer to one another. The molecules can then change from a gaseous state to a liquid state since they can no longer maintain their gaseous state
Hence, the reason is not an explanation of the assertion
Learn more about condensation:https://brainly.com/question/1287204
#SPJ1
Can I get some help for these chemistry questions .
1. C6H10O5 + 6O2 → 6CO2 + 5H2O
2. MgO + H2O → Mg(OH)2
3. 151.2444 grams of carbon dioxide are required to produce 3.44 moles of carbonic acid in the blood.
1. The complete, balanced chemical reaction for the burning of cellulose (C6H10O5), or wood, is:
C6H10O5 + 6O2 → 6CO2 + 5H2O
This reaction represents the combustion of cellulose in the presence of oxygen, resulting in the formation of carbon dioxide (CO2) and water (H2O).
2. The balanced equation for the reaction between magnesium oxide (MgO) and water (H2O) to produce magnesium hydroxide (Mg(OH)2) is:
MgO + H2O → Mg(OH)2
According to the equation, 1 mole of magnesium oxide reacts with 1 mole of water to produce 1 mole of magnesium hydroxide. Therefore, if 2.55 moles of magnesium oxide react, the same number of moles of magnesium hydroxide will be produced.
3. The balanced equation for the reaction between carbon dioxide (CO2) and water (H2O) to form carbonic acid (H2CO3) is:
CO2 + H2O → H2CO3
According to the equation, 1 mole of carbon dioxide reacts with 1 mole of water to produce 1 mole of carbonic acid. Therefore, if 3.44 moles of carbonic acid are produced, the same number of moles of carbon dioxide is required.
To calculate the mass of carbon dioxide, we need to know its molar mass, which is approximately 44.01 g/mol. Therefore, the mass of carbon dioxide required to produce 3.44 moles of carbonic acid is:
Mass = Moles × Molar mass
Mass = 3.44 moles × 44.01 g/mol
Mass = 151.2444 g
Therefore, 151.2444 grams of carbon dioxide are required to produce 3.44 moles of carbonic acid in the blood.
For more such qeustions on carbon dioxide visit:
https://brainly.com/question/21256960
#SPJ8
are two double bonds in
uble dash.
:0=C=O
NO2-
Answer:
Yes
Explanation:
There are in double dash :) ( = )
Answer:
yes
Explanation:
Because the double dash shows a double bond it simply means that two electrons from each atom are being shared
Element A has two isotopes. The first isotope is present 19.52% of the time and has a mass of 265.1.
The second isotope has a mass of 182.27. Calculate the atomic mass of element A. (To two decimals
places)
The atomic mass of element A is 198.39 (to two decimal places).
To calculate the atomic mass of element A, we need to consider the relative abundance of each isotope and its corresponding mass. The atomic mass is the weighted average of the masses of all the isotopes, taking into account their relative abundance.
Given:
Isotope 1: Relative abundance = 19.52%, Mass = 265.1
Isotope 2: Relative abundance = 100% - 19.52% = 80.48%, Mass = 182.27
To calculate the atomic mass, we multiply the relative abundance of each isotope by its mass and sum up the results.
Atomic mass = (Relative abundance of Isotope 1 * Mass of Isotope 1) + (Relative abundance of Isotope 2 * Mass of Isotope 2)
Atomic mass = (19.52/100 * 265.1) + (80.48/100 * 182.27)
Calculating the values:
Atomic mass = (0.1952 * 265.1) + (0.8048 * 182.27)
Atomic mass = 51.72752 + 146.661296
Atomic mass = 198.388816
Rounding to two decimal places, the atomic mass of element A is 198.39.
For more such question on mass. visit :
https://brainly.com/question/24191825
#SPJ8
What is one way humans can preserve biodiversity
Answer:
Reducing the amount of water you use, by having a 5-minute shower or not running the water when washing up the dishes, can help protect vital wetlands. Plant scientists are also working to help conserve by developing crop varieties that use less water.
Explanation:
Answer:
1. Most of the endangered organisms may represent a source of income.
2. The conservation or preservation may conflict with morals.
3. The role of the species or organisms might not be understood.
Explanation:
Biodiversity simply means the amount or number of living organisms that exist in the world.
The practice of protecting these existing living organisms for specific known purposes is regarded as the preservation or conservation of biodiversity.
This process or practice of preserving biodiversity is important to meet most of the human needs, such as generating income, source of food and fuel among others.
Question 10 of 23
Which characteristic makes a digital signal more useful than an analog signal
for storing information?
A. A digital signal includes a spectrum of colors.
B. A digital signal is more difficult to copy.
C. A digital signal cannot be heard by humans.
O D. A digital signal moves between a discrete number of values.
Answer: O D. A digital signal moves between a discrete number of values.
Explanation:
The digital signals are considered more reliable over the analog signals as they encode the information in a coded form. The bits or samples of the data are transmitted and converted into digital and numerical value. The stream of encoded data is in the form of continuous data at regular time intervals. It provides information in waveform and the data is in compact form. The data is in the form of binary bits 0 and 1 so greater the number of bits greater will be the greater will be the resolution of the information.
What are the 5 properties of muscles
A student in the lab accidentally poured 45 mL of water into a graduated cylinder containing 15 mL of 3.0 M HCL. What is the concentration of the new solution?
Answer:
The correct approach is "1 M".
Explanation:
The given values are:
Volume of HCL,
V₁ = 45 ml
In prepared solution,
V₂ = 15 ml
Concentration,
C₁ = ?
C₂ = 3.0 M
As we know,
⇒ [tex]V_1C_1=V_2C_2[/tex]
or,
⇒ [tex]C_1=\frac{V_2C_2}{V_1}[/tex]
On substituting the values, we get
⇒ [tex]=\frac{15\times 3}{45}[/tex]
⇒ [tex]=\frac{45}{45}[/tex]
⇒ [tex]=1 \ M[/tex]
calorimetry and specific heat lab report can someone please write this for me
If anyone still needed help on this, someone wrote out the student table on brainly.com, look up Lab: Calorimetry and Specific Heat.
The page should say something along the lines of please Please i need it Lab: Calorimetry and Specific Heat
This one should help you a lot more. Good luck.
Answer:
If anyone still needed help on this, someone wrote out the student table on brainly.com, look up Lab: Calorimetry and Specific Heat.
The page should say something along the lines of please Please i need it Lab: Calorimetry and Specific Heat
This one should help you a lot more. Good luck.
Explanation:
A strong acid, such as hydrochloric acid cannot be poured down a sink because it will react and dissolve the metal in the pipes. Yet a strong base, commonly found in drain cleaner, can be poured down a sink. A strong acid can be neutralized with a strong base, creating a salty water solution. What will happen when 10.0 g of hydrochloric acid were mixed with 10.5 grams of calcium hydroxide?
Answer:
15.2 grams of calcium chloride are produced and HCl is the limiting reactant.
Explanation:
Hello there!
In this case, according to the described scenario, it is possible to realize that the reaction between hydrochloric acid and calcium hydroxide is:
[tex]2HCl+Ca(OH)_2\rightarrow CaCl_2+2H_2O[/tex]
Whereas there is a 2:1 mole ratio of the acid to the base. In such a way, with the given masses, we can compute how much calcium chloride product is produced due to the chemical reaction via stoichiometry:
[tex]m_{CaCl_2}^{by HCl}=10.0gHCl*\frac{1molHCl}{36.46gHCl}*\frac{1molCaCl_2}{2molHCl} *\frac{110.98gCaCl_2}{1molCaCl_2} =15.2gCaCl_2\\\\m_{CaCl_2}^{by Ca(OH)_2}=10.5gHCl*\frac{1molCa(OH)_2}{74.09gCa(OH)_2}*\frac{1molCaCl_2}{1molCa(OH)_2} *\frac{110.98gCaCl_2}{1molCaCl_2} =15.7gCaCl_2[/tex]
Whereas we infer that the correct amount is 15.2 g since HCl is the limiting reactant as it produces the fewest grams of the desired product. Consequently, the calcium hydroxide is the excess reactant here.
Regards!
125.0 mL of 2.00 M NaCl solution is diluted to a concentration of 1.50 M. How many mL of water was added to the original volume? (Hint: must find V2 first) 1
166.7 ml
30.9 mL
41.7 ml
292 mL
(no links and please show work)
Answer:
Option A
Explanation:
As we know
C1V1 = C2V2
C1 = concentration of solution before dilution
V1 = Volume of solution before dilution
C2 = concentration of solution after dilution
V2 = Volume of solution after dilution
Substituting the given values in above equation, we get -
125 mL * 2.00 M = X mL * 1.50 M
X mL = 125 mL * 2.00 M / 1.50 M
X = 167 mL
Hence, option A is correct
By examining data from distant stars, astronomers can determine
if a star is moving away from or toward Earth. Which of the
following pieces of data would be most helpful in determining
the motion of a star?
A The star gives off blue-white light.
B
The star gives off mainly radio waves and X-rays.
C
The light spectrum given off by the star is shifted toward the
red end.
.
D
The surface temperature of the star is approximately 10,000°
Celsius.
Answer:
The answer is A ahahahha
Explanation:
Because it just is
A mole equals 6.02 x 10^23 . Answer these questions below.
1. How many ants are in 1.25 moles of ants?
2. How many moles of pencils are in 4.92 * 10^26 pencils?
3. How many molecules are in 0.26 moles of molecules?
4. How many moles of molecules are in 3.46 * 10^19 molecules?
5. 5.3 * 10^20 atoms are equal to how many moles of atoms?
6. 0.11 moles of atoms are equal to how many atoms?
Answer:
1. 1.25 mol ants x 6.02*10^23 ants/1 mol ants = 7.53*10^23 ants
2. 4.92*10^26 pencils x 1 mol pencils/6.02*10^23 pencils = 817 mol pencils
3. 0.26 mol molecules x 6.02*10^23 molecules/1 mol molecules = 1.6*10^23 molecules
4. 3.46*10^19 molecules x 1 mol molecules/6.02*10^23 molecules = 5.75*10^-5 mol molecules
5. 5.3*10^20 atoms x 1 mol atoms/6.02*10^23 atoms = 8.8 mol atoms
6. 0.11 mol atoms x 6.02*10^23 atoms/1 mol atoms = 6.6*10^22 atoms
I would suggest looking into "dimensional analysis" for help with this type of material. Dimensional analysis will stick with you all throughout chemistry, so picking it up will be extremely beneficial.
Explain what you think controls a material’s porosity
The primary porosity of a sediment or rock consists of the spaces between the grains that make up that material. The more tightly packed the grains are, the lower the porosity.