Answer:
Exfoliation involves the removal of the oldest dead skin cells on the skin's outermost surface. Exfoliation is involved in all facials, during microdermabrasion or chemical peels. Exfoliation can be achieved by mechanical or chemical means.
Explanation:
I did copy off internet!
:P
What is the mass of 5.2 x 10^21 atoms of Vanadium?
Answer:
Mass = 0.44 g
Explanation:
Given data:
Mass of vanadium = ?
Number of atoms of vanadium = 5.2 × 10²¹ atoms
Solution:
It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance.
The number 6.022 × 10²³ is called Avogadro number.
1 mole = 6.022 × 10²³ atoms
5.2 × 10²¹ atoms × 1mol / 6.022 × 10²³ atoms
0.86× 10⁻² mol
0.0086 mol
Mass of vanadium:
Mass = number of moles × molar mass
Mass = 0.0086 mol × 50.9 g/mol
Mass = 0.44 g
1. How does the tendency of metal atoms to
lose valence electrons explain the periodic trends
of properties found in representative metal
elements
Explanation:
The tendency of metals to lose electrons is a measure of their electropositivity or metallicity.
Electropositivity is a measure of the tendency of atoms of an element to lose electrons. It is closely related to ionization energy and electronegativity of an element.
The lower the ionization energy of an element, the more electropositive or metallic an element is. Across a period, from left to right, electropositivity or metallicity decreases and from top to down a group, it increases. Metals are found on the left of the periodic table.Emily learns that ancient astronomers, such as Ptolemy, created a model of the solar system based only on what they could see with their eyes. Describe Ptolemy's model of the solar system and how he came to his conclusions. Then describe Galileo's model of the solar system. Explain how Galileo proved that his model was correct and that Ptolemy’s was not correct.
Explanation:
Galileo found Venus went through the entire phase cycle, proving that she revolved completely around the Sun, as predicted by Copernicus in his heliocentric model. ... The phases of Venus could not be explained by Ptolemy's Geocentric Model. Galileo knew that the Roman Catholic Church was incorrect.
PLEASE HELP IM TIMED create an analogy for the motion of atoms in solids,
liquids, and gases, so she compared them to marbles
in a tray
A solid is like the tray being shaken and the manies
moving around it, and a liquid is like the tray being
shaken slowly and all the marbles moving in their
positions
A solid is like the tray being shaken slowly and all
the marbles moving in their positions, a liquidi is like
the tray being shaken and the marbles moving
around it, and a gas is like the tray being shaken
hard and the marbles moving vigorously around it.
A gas is like the tray being shaken slowly and all the
marbles moving in their positions, and a solid is like
the tray being shaken hard and the marbles moving
vigorously around it
Aliquid is like the tray being shaken hard and the
marbles moving vigorously around it and a gas is
like the tray being shaken slowly and all the marbles
moving in their positions.
Markthisandretum
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1. A student combined silver nitrate and sodium
chloride. She observed a white solid precipitate
formed. The mass of the silver chloride precipitate
was measured to be 150.15 g. According to the Law
of Conservation of mass, what is the predicted mass
of the sodium nitrate produce
AgNO
AgCl white
precipitate in
solution
Naci
NaNO
solution
solution
300.23 g
300.23 90
+ NaCl
AgNO3
AgC1
+
NaNO3
silver nitrate
and sodium chloride
yield silver
chloride
and
sodium nitrate
Answer:
150.08 g
Explanation:
According the law of conservation of mass, mass can neither be created nor destroyed but is converted from one form to another.
As a result of this, the total mass of reactants must be equal to the total mass of products.
If this is so, we have been told that the mass of AgCl is 150.15 g, the total mass of products is 300.23g.
Therefore; mass of NaNO3 = 300.23 g - 150.15 g = 150.08 g
sodium combines with water to produce a sodium hydroxide and hydrogen gas. which word equation respresents this violent reaction?
Answer:
Na(s) + H₂O (l) → NaOH(aq) + H₂(g).
Explanation:
answer is this thank you I hope it helps you pls like
Matter is composed of exceedingly small particles called atoms. An atom is the smallest unit of an element that can participate in a _______. A macroscopic sample of an element contains an incredibly large number of atoms, all of which have identical _______. Atoms of one element differ in properties from atoms of all other elements. A compound consists of atoms of two or more elements combined in a _______. Atoms are neither _______ during a chemical change; they're instead rearranged to yield substances that are different from those present before the change.
Answer: 1) chemical change 2) chemical properties 3) ratio? 4) created nor destroyed
Explanation: 1) Matter is composed of exceedingly small particles called atoms. An atom is the smallest unit of an element that can participate in a chemical change. 2) A macroscopic sample of an element contains an incredibly large number of atoms, all of which have identical chemical properties. 3) A compound consists of atoms of two or more elements combined in a small, whole-number ratio. In a given compound, the numbers of atoms of each of its elements are always present in the same ratio. 4) Atoms are neither created nor destroyed during a chemical change, but are instead rearranged to yield substances that are different from those present before the change
Which of the following is the number of hydrogen atoms in a mole of hydrogen gas
at STP?
a) 224
b) 6,02 x 1023
c) 1,20 x 1024
d) 2.016
e) 1.008
true or false
1. resistance provides friction to electron movement
2.high resistance will speed up electron movement
3.a circuit is an open path for electrons to move through
4. in a circuit, electrons move from the low voltage area to the higher
5. in a circuit, the light bulb is called the load
Answer:1
Explanation: friction is showing us how in the past
What is the mass of Silver in 3.45g AgS?
Answer:
Mass = 2.59 g
Explanation:
Given data:
Mass of AgS = 3.45 g
Mass of silver = ?
Solution:
Number of moles of AgS:
Number of moles = mass/molar mass
Number of moles = 3.45 g/ 139.93 g/mol
Number of moles = 0.024 mol
1 mole of AgS contain 1 mole of Ag.
0.024 mol contain 0.024 mol of Ag.
Mass of silver:
Mass = number of moles × molar mass
Mass = 0.024 mol × 107.86 g/mol
Mass = 2.59 g
Sodium chloride can be produced by the reaction of sodium metal with chlorine gas. Which is the limiting reactant if 6.70 moles of Na reacts with 3.20 moles of chlorine gas
Answer:
Chlorine gas.
Explanation:
Hello!
In this case, the undergoing chemical reaction is:
[tex]2Na+Cl_2\rightarrow 2NaCl[/tex]
Thus, given the moles of reacting both sodium and chlorine, we compute the moles of sodium chloride yielded by each reactant by considering the 2:2 and 1:2 mole ratios:
[tex]n_{NaCl}^{by\ Na}=6.70molNa*\frac{2molNaCl}{2molNa}=6.70molNaCl \\\\n_{NaCl}^{by\ Cl_2}=3.20molCl_2*\frac{2molNaCl}{1molCl_2}=6.40molNaCl[/tex]
Thus, since chlorine yields less moles of sodium chloride, we infer it is the limiting reactant.
Best regards!
Rhenium has two naturally occurring isotopes, Re-185 and Re-187. The relative atomic mass of rhenium is 186.2. What are the natural abundances of these isotopes
Answer:
The natural abundance of Re-185 is 40% and of Re-187 is 60%
Explanation:
Relative atomic mass is defined as the sum of the mass of each isotope times its relative abundances.
Is Rhenium has only 2 isotopes and the abundances are X and Y we can write:
X + Y = 1 (1)
And:
185X + 187Y = 186.2 (2)
Where X is abundance of Re-185 and Y abundance of Re-187
Replacing (1) in (2):
185X + 187(1-X) = 186.2
185X + 187-187X = 186.2
-2X = -0.8
X = 0.4 = 40%
And Y = 100% - 40% = 60%
The natural abundance of Re-185 is 40% and of Re-187 is 60%Is my answer correct
Answer:
You're answer is correct. The third answer is correct.
Explanation:
Producers have the most energy, since they gain energy directly from the sun. Their energy is then passed up this upside down pyramid, which the energy is decreased by about 10% each time.
#teamtrees #WAP (Water And Plant)
How is reproduction and life are connected?
Answer:
reproduction and life are connected because when you reproduce you are creating life.
What kind of reaction is potassium+ nitrogen
Answer:
Potassium nitrate is a chemical compound with the chemical formula KNO3. It is an ionic salt of potassium ions K+ and nitrate ions NO3−, and is therefore an alkali metal nitrate. It occurs in nature as a mineral, niter (or nitre in the UK). It is a source of nitrogen, and nitrogen was named after niter.
Explanation:
How many moles are in 99.5 grams of titanium? Round your answer to the nearest hundredth. Be sure to include units.
Answer:
1000
Explanation:
If 200,4 g of water is mixed with 101.42 g of salt, the mass of the final solution
would be reported as
A) 302 8.
B) 3008
C) 301.8 8.
D) 301.828
Answer:
C) 301.8
Explanation:
Hello!
In this case, since the solution is composed by water and salt, the total resulting mass comes up from adding the mixed mass of each one:
[tex]m_{sol}=m_{w}+m_{salt}[/tex]
Thus, we plug in to obtain:
[tex]m_{sol}=200.4g+101.42g\\\\m_{sol}=301.8g[/tex]
Therefore, the answer should be C) 301.8 as it has four significant figures.
Best regards!
Explain why photosynthesis is much slower in underwater plants.
Answer
There is not as much sunlight underwater and therefore less energy can be absorbed therefore a slower process of photosynthesis.
Explanation:
The ratio molecular mass of gas A and B is 1.25 calculate the ratio of rate of diffusion of the gases
Answer:
i will tell your teacher that u uding online cheats to answer yout homeworks hhaahaha
Explanation:
good luck brooo hahahha
The value of Henry's law constant for oxygen in water at 242C is 1.66 x 1 ox M/torr. b. c. Calculate the solubility of oxygen in water at 25aC when the total external pressure is I atm and the mole fraction of oxygen in the air IS 020. Calculate the solubility at the same temperature with the same atmospheric composition but at an increased pressure of 2 atn. What would happen to the solubility of the oxygen gas if the temperature was increased?
What happens to the energy released by an exothermic reactions
Answer:
In an exothermic reaction, the products are at a lower energy than the reactants. The difference between the energy of the reactants and the energy of the products is called the enthalpy change (∆H) of the reaction. For an exothermic reaction, the enthalpy change is always negative.
please explain the flow of energy through a food web, and please explain the flow of matter through a food web
Answer: ENERGY: A food chain is a linear sequence of organisms through which nutrients and energy pass as one organism eats another; the levels in the food chain are producers, primary consumers, higher-level consumers, and finally decomposers. These levels are used to describe ecosystem structure and dynamics.
MATTER: When one organism eats another, the matter, or carbon, nitrogen, and other essential elements, are transferred from one to the other. These elements move from the producers, to the consumers, and eventually to the decomposers, cycling the matter through the ecosystem.
Explanation: look up
Do you think more chemical reactions that occur in the human body are endothermic or exothermic? Justify your answer.
Answer:
Exothermic
Explanation:
We as humans do not absorb heat. A good way to think about it is that when we workout we use energy from our body which causes our body temperature to rise. The energy used from food maintains our blood, respiration, and other systems in optimal condition. This requires energy from our body which ends up leaving the body as heat.
What is the overall voltage for the nonspontaneous redox reaction involving
Mg and Cu and their ions?
A. 0.34 + (-2.37)
B. -2.37 - 0.34
C. 2.37 - 0.34
D. 0.34 +2.37
SUBMIT
Answer: B -2.37 -0.34
Explanation: A P E X
The redox reaction consists of the reduction and the oxidation halves and involves the transfer of electrons. The overall voltage for the Mg and Cu is 0.34 - (-2.37). Thus, option C is correct.
What is a nonspontaneous redox reaction?A nonspontaneous redox reaction is the loss and gain of the electrons when an external source of voltage is applied to initiate the electrochemical reaction.
The overall voltage of the redox reaction can be given by the oxidation and the reduction of half of the cell as,
Oxidation half: Mg(s) → Mg₂⁺ + 2e⁻ E° = -2.37 v
Reduction half: Cu₂⁺ + 2e⁻ → Cu(s) E° = + 0.34 v
The overall voltage of the cell (E° cell) is calculated as,
E° cell = E°(reduction) - E°(oxidation)
= +0.34 - (-2.37)
= 2.71 v
Therefore, option C. 0.34 - (-2.37) is the overall voltage for the nonspontaneous redox reaction.
Learn more about redox reaction here:
https://brainly.com/question/14217644
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Your question is incomplete, but most probably your full question was, What is the overall voltage for a redox reaction with the half-reactions Mg(s) → Mg₂⁺ + 2e⁻ and Cu₂⁺ + 2e⁻ → Cu(s)?
A. -2.37 - 0.34
B. 0.34 - 2.37
C. 0.34 - (-2.37)
D. 2.37 - 0.34
A shoe was thrown across the room and it hit a desk directly across, the shoe flew 5m within 6 seconds, what is my velocity?
Answer:
[tex]velocity = \frac{displacement}{time} \\ = \frac{5}{6} \\ velocity = \frac{5}{6} m {s}^{ - 1} [/tex]
White vinegar is a 5.0% by mass solution of acetic acid in water. If the density of white
vinegar is 1.007 g/cm3
, what is the pH?
The pH = 2.41
Further explanationGiven
5.0% by mass solution of acetic acid
the density of white vinegar is 1.007 g/cm3
Required
pH
Solution
Molarity of solution :
[tex]\tt M=\dfrac{\%mass\times \rho\times 10}{MW~acetic~acid}\\\\M=\dfrac{5\times 1.007\times 10}{60}\\\\M=0.839[/tex]
Ka for acetic acid = 1.8 x 10⁻⁵
[H⁺] for weak acid :
[tex]\tt [H^+]=\sqrt{Ka.M}[/tex]
Input the value :
[tex]\tt [H^+]=\sqrt{1.8\times 10^{-5}\times 0.839}\\\\(H^+]=0.00388=3.88\times 10^{-3}\\\\pH=3-log~3.88=2.41[/tex]
White vinegar is a 5.0% by mass solution of acetic acid in water and if the density of white vinegar is 1.007 g/cm³ then the pH of solution is 4.8.
How we calculate pH?pH of any solution will be calculated as:
pH = - log[H⁺], where
[H⁺] = concentration of H⁺ ions
In this question we will calculate the concentration of H⁺ ions as:
[H⁺] = √Ka.M, where
Ka = acid dissociation constant for acetic acid = 1.8 x 10⁻⁵ (known)
M is molarity and this can be calculated as:
M = (% mass × density × 10) / Molar mass of acid
Given that,
% mass = 5.0% by mass solution of acetic acid
density = 1.007 g/cm³
Molar mass of acetic acid = 60
Now putting all these values on the above equation, we get
M = (5 × 1.007 × 10) / 60 = 0.839
Now, we calculate the concentration of H⁺ ions by putting values on that equation as:
[H⁺] = √(1.8 x 10⁻⁵)(0.839)
[H⁺] = 1.5 x 10⁻⁵
So, pH of the solution will be calculated as:
pH = -log(1.5 x 10⁻⁵)
pH = -(-4.8)
pH = 4.8
Hence, pH is 4.8.
To know more about pH, visit the below link:
https://brainly.com/question/10313314
Chemistry
Definition in your own words
Will check if you got it from online.
Word: Phase change
Please Hurry
How is thermal energy transferred during conduction? Check all that apply.
Thermal energy is transferred between particles that are not touching each other.
Thermal energy is transferred between particles that are in direct contact with each other.
Thermal energy is transferred between objects of different temperatures.
Thermal energy is transferred between objects of the same temperature. Thermal
energy is transferred from slow-moving particles to fast-moving particles. Thermal
energy is transferred from fast-moving particles to slow-moving particles.
Answer:
B,C,F
Explanation:
Answer:
b c f
Explanation:
At what temperature does ice start to melt
Answer:
Explanation:
The answer is 32°F or 0° Celsius.
Hope it helped you.
What happens when the sunspots rotate?
Answer:
Over time, the Sun's differential rotation rates cause its magnetic field to become twisted and tangled. The "tangles" in the magnetic field lines can produce very, very strong localized magnetic fields. Places where "ropes" of bundled field lines "break" the surface of the Sun are active regions where sunspots form.