Answer:
Zn, Cu, Fe, Mn, Co, Mo
Explanation:
Biogenic elements are chemical elements constantly present in organisms and having definite biological significance(Bowen, 1966).
There are many of these biogenic elements in nature. Among the elements of the d-block, Zn, Cu, Fe, Mn, Co, Mo are worthy of mention among others.
Free ions of d- block metals are not found in the body. The elements are present in the form of bioinorganic complexes of the respective metals. They commonly exist as co-factors of proteins that carry out essential biological functions.
What could be the molecular formula for a compound that contains 39.33% C, 8.269% H, and 52.40% O?
a) C4H2O
b) CHO
c) C3H6O
d) C2H5O2
Answer:
d) C₂H₅O₂
Explanation:
Molecular formula is a whole-number ratio of atoms presents in a molecule. The percentage given is in mass. Thus, we need to convert this percentage to moles using atomic mass of each atom and, in this way, we can solve for the ratio of atoms and molecular formula as follows:
C = 39.33g * (1mol / 12.01g) = 3.275mol
H = 8.269g * (1mol / 1.005g) = 8.228mol
O = 52.40g * (1mol / 16g) = 3.275mol
To obtain the ratio we must divide each amount of moles in the low number of moles (Moles of O or C):
C = 3.275mol / 3.275mol = 1
H = 8.229mol / 3.275mol = 2.5
O = 3.275mol / 3.275mol = 1
Multiplying this ratio in 2 (To obtain the whole-number ratio):
C = 1*2 = 2
H = 2.5*2 = 5
O = 1*2 = 2
The molecular formula is:
C₂H₅O₂
And right answer is:
d) C₂H₅O₂which of these does not have volume
a. air
b. a lake
c. energy
d. a sponge
Answer:
c
Explanation:
energy does not have volume
Answer:
C.energy.Explanation:
Please mark my answer as a brainliest. ❤❤❤❤How would you define the period of a pendulum?
A.) time it takes the pendulum to make one full back-and-forth swing
B.) time it takes the pendulum to swing forward only
C.) time it takes the pendulum to swing back only
A. The period of a pendulum can b defined as the time it takes the pendulum to make one full back-and-forth swing.
What is period of a pendulum?The period of a pendulum is defined as the time taken by the pendulum to finish one full oscillation and is denoted by letter "T".
The period of oscillation of a pendulum is calculated as follows;
T = 2π√(L/g)
where;
L is the length of the pendulumg is acceleration due to gravity = 9.8 m/s²T is the period of the oscillation of the pendulumThe period of a pendulum does not depend on the mass of the ball, but only on the length of the string.
Thus, we can conclude that, the period of a pendulum can b defined as the time it takes the pendulum to make one full back-and-forth swing.
A full back ad forth swing makes one complete oscillation.
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Which statement best reflects a change in climate?
It's very windy today and will rain later.
Droughts in California have become more common over the past few decades.
There is a hurricane forming off the coast of Florida.
Tropical climates are likely to be wet and warm. sorry science wasnt a subject i could pick from.
Answer:
droughts in California have become more common in California
Explanation:
Climate is weather over time which means that the first and the third one are just isolated incidents and the last answer choice shows climate but it doesn't show a change in climate
Which compound accepts electrons from NADH , producing a compound that can pass through the inner membrane?
1. oxaloacetate
2. aspartate
3. glutamate
4. a-ketoglutarate
Answer:
The correct answer is - 1. oxaloacetate.
Explanation:
During the electron transport chain, the oxaloacetate is converted to aspartate by the reduction of NADH and accepting electrons in the mitochondria. Aspartate is then moved through the inner membrane to the cytosol.
This is the reaction also known as the synthesis of the aspartate. Aspartate either again converted to OAA (oxaloacetate) or move to the biosynthesis of proteins and biosynthesis of purine and pyrimidines.
Which of the following health conditions can be controlled by practice and personal hygiene
Answer:
you didn't show the options
Explanation:
What is the energy of an X-ray with a frequency of 6.35 x 108 Hz?
Answer:
3x10 16hz 16 small above 10
Explanation:the frequency of any wave is (wave speed)/(wavelength)
The speed of light is 3x10 m/s. that's 30 million quartz
What is the density of Iodine gas at 2.36 atm and 65.0 C?
The density : 21.63 g/L
Further explanationThe gas equation can be written
[tex]\large {\boxed {\bold {PV = nRT}}}[/tex]
where
P = pressure, atm
V = volume, liter
n = number of moles
R = gas constant = 0.08206 L.atm / mol K
T = temperature, Kelvin
T = 65+273=338 K
P=2.36 atm
MW Iodine gas (I₂)=254
The density :
[tex]\tt \rho=\dfrac{P\times MW}{RT}\\\\\rho=\dfrac{2.36\times 254}{0.082\times 338}=21.63~g/L[/tex]
!!!!!!!!!!!!!!!!!!!!
barium chloride + sodium phosphate
Answer with double replacement
Answer:
Barium chloride + Sodium phosphate → barium phosphate + sodium chloride
Explanation:
Double replacement:
It is the reaction in which two compound exchange their ions and form new compounds.
AB + CD → AC +BD
Chemical equation:
BaCl₂ + Na₃PO₄ → Ba₃(PO₄)₂ + NaCl
Balanced chemical equation:
3BaCl₂ + 2Na₃PO₄ → Ba₃(PO₄)₂ + 6NaCl
The cation and anion of both reactants are exchanged with each other.
Ba²⁺ react with PO₄³⁻ and form Ba₃(PO₄)₂ while Cl⁻ react with Na⁺ and form sodium chloride.
Molecular equation:
Barium chloride + Sodium phosphate → barium phosphate + sodium chloride
A sample of gas occupies a volume of 571.5 mL at 0.944 atm and 10 oC. Determine the pressure of this sample at 1.183 L and 32 oC.
Answer:
0.491 atm
Explanation:
Initial volume V1 = 571.5 mL = 0.5715 L
Initial Pressure P1 = 0.944 atm
Initial Temperature T1 = 10 oC + 273 = 283 K (Converting to kelvin units)
Final Temperature T2 = 32 oC + 273 = 305K (Converting to kelvin units)
Final volume V2 = 1.183 L
Final Pressure P2 = ?
These parameters related by the combined gas law;
P1V1 / T1 = P2V2 / T2
Mke P2 subject of formular;
P2 = P1 V1 T2 / V2 T1
P2 = 0.944 * 0.5715 * 305 / 1.183 * 283
P2 = 0.491 atm
UV-B light is harmful to the human body and can cause irreparable cell damage. How much energy per photon is associated with UV-B rays with a wavelength of 305 nm?
The energy of the waves is 6.5 * 10^-19 J.
What is the energy?The energy of the wave could be obtained from the wavelength of the wave by by the use of the formula shown below;
E = hc/λ
h = Plank's constant
c = speed of light
λ = wavelength
Now we have;
h = 6.6 * 10^-34 Js
c = 3 * 10^8 m/s
λ = 305 * 10^-9
E = 6.6 * 10^-34 Js * 3 * 10^8 m/s/ 305 * 10^-9
E = 6.5 * 10^-19 J
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How many particles are in 47.7 g of Magnesium? (Round the average
atomic mass to two numbers after the decimal)
Answer:
1.18 × 10²⁴ particles Mg
General Formulas and Concepts:
Chemistry - Atomic Structure
Reading a Periodic TableUsing Dimensional AnalysisAvogadro's Number - 6.022 × 10²³ atoms, molecules, formula units, etc.Explanation:
Step 1: Define
47.7 g Mg
Step 2: Identify Conversions
Avogadro's Number
Molar Mass of Mg - 24.31 g/mol
Step 3: Convert
[tex]47.7 \ g \ Mg(\frac{1 \ mol \ Mg}{24.31 \ g \ Mg} )(\frac{6.022 \cdot 10^{23} \ particles \ Mg}{1 \ mol \ Mg} )[/tex] = 1.18161 × 10²⁴ particles Mg
Step 4: Check
We are given 3 sig figs. Follow sig fig rules and round.
1.18161 × 10²⁴ particles Mg ≈ 1.18 × 10²⁴ particles Mg
How many grams are in 1 mole of Ar?
Answer: 39.948 grams
Explanation:
The SI base unit for amount of substance is the mole. 1 mole is equal to 1 moles Ar, or 39.948 grams
On the Moon the gravity is approximately 1/6 of that on Earth. If an object has a mass of 120
grams on Earth, what is its weight on the Moon?
Answer:
Before I answer I feel that I should provide some scientific background as to how you would go about determining the answer.
First point that’s important for you to understand is the following formula
F = G∗(M1∗M2)/d2
Where G is your gravitational constant, which means that comparing the two weights it won’t change and we don’t really have to worry ourselves too much about it.
Secondly we have the masses of the two individual objects, M1 and M2, in this case M1 is going to be 120 pounds.
Then you have d which is the distance between the centres of the two objects.
The second thing you need to understand is the fine print in the question. You asked how much you would weigh given that you weigh 120 pounds on Earth. The question from a pure science view is flawed as you don’t infact weigh 120 pounds, rather you have a mass of 120 pounds which will remain a constant. Your weight on Earth is actually 530 Newtons
(120lb=54,4311kg)
(54,4311kg*9.8) = approximately 530N
Now assuming you are right and the moon has a sixth of the earths mass, that would mean that you would weigh a sixth of it.
But wait theres more, because the radius of the moon is smaller it will have an impact. the radius of the moon infact is a sixth of the earths, which means that you will be multiplying by 36(because you are making the divisor a sixth smaller, but also squaring it)
this would mean that you would weigh six times as much on the moon as on Earth, which we know is not true. This implies you made a mistake with the mass of the moon compared to that of the Earth. So upon googling it.
Mass of Earth
5.972 × 10^24 kg
Mass of Moon
7.34767309 × 10^22
kilograms
Just looking at it the difference is about 200 times, which means that you probably misinterpreted the data, the gravitational attraction of the moon is a sixth of the Earths, which means you would weigh about 530/6N or to the casual viewer about 88 N
Note : I rounded and abstracted a lot because I feel its the gist of the answer and the understanding that’s important, you are welcome to contact me if you feel anything is incomplete or unclear. I did most of the math quickly and am liable to mistakes but the science is right(unless ofc you feel like bringing relativity in, but that’s a whole other can of worms
Explanation:
Yess
Answer:
19.92 pounds :)
Define the following and give an example of each:_______.
(a) dispersion force
(b) dipole-dipole attraction
(c) hydrogen bond
London Dispersion force or Van de Waals force is a temporary attractive force which are the weakest and occur between nonpolar noble gases and same charges. This force is weaker because they have more electrons that are farther from the nucleus and are able to move around easier.
Example: [tex]N_2[/tex], [tex]F_2, \ I_2[/tex]
_____________________________________[tex]\huge\textbf{Dipole - Dipole Forces}[/tex]
Dipole force is present between the polar molecules. Polar molecules are those molecules which have slightly negative and slightly positive charge. Dipole-dipole forces are attractive forces between the positive end of one polar molecule and the negative end of another polar molecule.
Example: HCl, HF, [tex]CHCl_3[/tex]
_____________________________________[tex]\huge\textbf{Hydrogen Bonding}[/tex]
It is a special type of dipole force present between polar molecules, it is formed between Hydrogen atom which forms positive ion, and the other negative ion. It results from the attractive force between a hydrogen atom covalently bonded to a very electronegative atom such as a N, O, or F atom. The hydrogen bond is one of the strongest intermolecular attractions, but weaker than a covalent or an ionic bond.
Example: Every polar molecule which has hydrogen has hydrogen bonding i.e. [tex]H_2O, NH_3[/tex]
_____________________________________Best Regards,'Borz'Using the square-bracket notation, express the concentration of ions in a solution that is 0.811 M in aluminum sulfate [Al2(SO4)3].
[Al^3+] = ____ M
[SO4^2−] = ____ M
Answer:
[Al³⁺] = 1.62 M
[SO₄²⁻] = 2.43 M
Explanation:
Step 1: Given data
Molar concentration of Al₂(SO₄)₃: 0.811 M
Step 2: Write the reaction for the ionization of Al₂(SO₄)₃
Al₂(SO₄)₃(aq) ⇒ 2 Al³⁺(aq) + 3 SO₄²⁻(aq)
Step 3: Calculate the molar concentration of Al³⁺
The molar ratio of Al₂(SO₄)₃ to Al³⁺ is 1:2. The molarity of Al³⁺ is 2/1 × 0.811 M = 1.62 M.
Step 4: Calculate the molar concentration of SO₄²⁻
The molar ratio of Al₂(SO₄)₃ to SO₄²⁻ is 1:3. The molarity of SO₄²⁻ is 3/1 × 0.811 M = 2.43 M
The concentration of the aluminium ion is 0.4055 M while the concentration of the sulfate ion is 0.270 M.
We know that the following reaction occurs for the dissolution of Al2(SO4)3 in water;
Al2(SO4)3(s) ----> 2Al^3+(aq) + 3SO4^2-(aq)
To find the concentration of each of the ions;
Concentration of Al^3+ = 1/2 × 0.811 M = 0.4055 MSo using the square bracket notation to indicate concentration;
[Al^3+] = 0.4055 M
Concentration of SO4^2- = 1/3 × 0.811 M = 0.270 MSo using the square bracket notation to indicate concentration;
[SO4^2−] =0.270 M
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what makes up from zero to four percent of the atmosphere?
Label the element from which it is easier to remove an electron argon or bromine
The element from which it is easier to remove an electron between Argon and Bromine is Bromine.
This can be explained by electron affinity.
Electron affinity is defined as amount of the energy released when one mole of electron is added to one mole of atom or to the outermost or valence shell to form anion. It is the measure of attraction existing between atom and electron.
Electron affinity of Bromine is 324.537 kJ/mol and electron affinity of Argon is -96 kJ/mol. A higher electron affinity indicates that an atom accepts or removes the electrons more easily and low electron affinity means that an atom do not accept or remove electrons as easily.
Bromine has atomic number 35, which means it has 35 protons in nucleus. It has 35 electrons and for a bromine atom to become a 1- bromide ion, it will have to gain an electron. If it loses electrons, it receives a positive charge because it has more protons than electrons.
Argon is a noble gas element. It means argon is highly stable because it has full outer shell of electrons. Argon has low affinity. Therefre, it does not lose or gain electrons because it is already stable.
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What is stoochiometry?
Answer:
Stoochiometry is the quantitative relation between the number of moles ( and therefore mass ) of various products and reactants in a chemical reaction.Explanation:
I hope l helped you. Please follow me. ❤❤❤Select each correct answer. More than one answer may be correct. Four atoms of hydrogen combine with one carbon atom to form CH4, but only two hydrogen atoms combine with one oxygen atom to form H2O. Which of the following helps to explain why? Hydrogen has one valence electron. Metallic bonds form between positively charged metal ions and delocalized electrons. Atoms may share electrons in order to fill their electron shells. Oxygen has two vacancies in its electron shell, but carbon has four vacancies.
how is the mole of a used to express the mass of a substance explain
Answer:
See explanation
Explanation:
The mole refers to the amount of substance contained in 12 g of carbon-12. It was arbitrarily related to the number of elementary entities in 12 g of carbon -12 by Prof. Avogadro.
The number of moles of a substance is obtained as the mass of the substance divided by the mass of one mole of the substance (molar mass). Hence when the number of moles is known, the mass is now;
number of moles * molar mass
Draw a structural formula of an alkene or alkenes (if more than one) that undergo acid-catalyzed hydration and without rearrangement give 1-methylcyclohexanol as the MAJOR product. Ignore stereochemistry. If your answer includes more than one alkene, just draw both structures. Do not separate the formulas with + or any other sign.
Answer:
See explanation and image attached
Explanation:
The acid-catalyzed hydration of alkenes is an ionic reaction. Being an ionic reaction, a carbocation is formed in the process. This carbocation is capable of rearrangement to yield different products based on thermodynamic stability.
Remember that the order of stability of carbocations is; methyl< primary<secondary< tertiary. The rearrangement of carbocations leads to the formation of more stable intermediates and consequently more stable products.
However, the alkene in the image shown yields 1-methylcyclohexanol without carbocation rearrangement.
how many moles are in 47.5 g of Ca?
A.2.85 e 25
B.1.18 mol
C. 7.89 e-23
D.1900 mol
What graph would you use if you wanted to compare similar data for several individual items or events?
A Bar graph
B Pie graph
Line graph
Answer:
A. Bar graph
Explanation:
Bar graphs are used to compare things between different groups or to track changes over time.
Answer:
option a, bar graph
Explanation:
- a graphic means of quantitative comparison by rectangles with lengths proportional to the measure of the data or things being compared
What is the acceleration of a 50kg object pushed with a force of 500 Newton’s
Answer:
10 m/s²Explanation:
The acceleration of an object given it's mass and the force acting on it can be found by using the formula
[tex]a = \frac{f}{m} \\ [/tex]
f is the force
m is the mass
From the question we have
[tex]a = \frac{500}{50} = \frac{50}{5} = 10 \\ [/tex]
We have the final answer as
10 m/s²Hope this helps you
please help. i’ve been gone for school for 1 week and half and i’m totally lost.
Can someone give me a title idea for the Science Investigatory Project?
Thx for your idea :)
what element has 20 protons 25 neutrons and 20 electrons
Answer: calcium
Explanation: a periodic table can tell you how many protons have, and from this we can see that the answer is calcium
A piece of lead wire has a diameter of 0.470mm. If less has a density of 11.3g/cc, how long(in metres) should you cut a piece of wire to obtain 0.0236 moles of lead
The length of lead wire in meters is 2.48 m.
What is the mass of lead in the wire?The mass of lead in the wire is calculated as follows:
mass = moles * molar massmoles of lead = 0.0236 moles
molar mass of lead = 207
mass of lead = 0.0236 * 207
mass of lead = 4.8852 g
The length of the is determined as follows:
volume = mass/densityvolume of wire = 4.8852/11.3
volume of wire = 0.432 cm³
diameter of lead wire = 0.470 mm = 0.047 cm
radius of the lead wire = 0.047 cm * 0.5 = 0.0235 cm
Assuming the lead wire is in the shape of a cylinder:
volume of the cylindrical lead wire = πr²l
l = volume/πr²
length of lead wire = 0.432/3.142 * 0.0235²
length of lead wire = 248.967 cm
length of lead wire in meters = 2.48 m
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