Answer: physically
Explanation: it's a physical change because the air that fills it up does not affect its chemical compound like I'd you mix metal in salt water
11-Which of the following would NOT be a Compound?
A?
B?
C?
D?
Answer:
A because it is not small enough
Explanation:
It's a of c Yea a or so pick that
A piece of string is found to be 35.9 meters long how long is the string in inches?
Answer:
1413.386
Explanation:
What is Darwin's name for species that do not appear to have changed for millions of years?
Since, the options have not been given the question is incomplete.
What is Darwin's name for species that do not appear to have changed for millions of years?
a.
Dinosaurs
b.
Living fossils
c.
Old souls
d.
Ancient moderns
Answer: b. Living fossil
Explanation:
In 1859 Charles Darwin proposed the term living fossil, that means a species or group of species that had not changed in terms of evolutionary context thus can be useful in tracing the extinct or previously existing forms of life. The examples of the living fossils are horseshoe crabs, ginkgo (Conifers) and tuatara. These group of animals were existed unchanged in the Ordovician, Permian, and Triassic periods respectively with few surviving species.
Answer:
the answer is living fossils so it would be b
Explanation:
how do i know i took the test
3) Tears are produced by the lacrimal glands located:
A) above the lateral canthus of each eye
B) below the medial canthus of each eye
C) below the lateral canthus of each eye
D) above the medial canthus of each eye
E) behind the nasal bones
What is a molecule contains the genetic instructions for the development and functioning of all living organisms found in the nucleus of a cell
if Fe(NO3)3 is dissolved in enough water to make exactly 323 ml of solution, what is the molar concentartion of nitrate ion g
The given question is incomplete. the complete question is : If 5.15 g[tex]Fe(NO_3)_3[/tex] is dissolved in enough water to make exactly 323 ml of solution, what is the molar concentartion of nitrate ion.
Answer: The molar concentartion of nitrate ion is 0.195.
Explanation:
Molarity of a solution is defined as the number of moles of solute dissolved per Liter of the solution.
Given : 5.15 g of [tex]Fe(NO_3)_3[/tex] is dissolved
Volume of solution = 323 ml
[tex]Molarity=\frac{n\times 1000}{V_s}[/tex]
where,
n= moles of solute
[tex]Moles=\frac{\text{Given mass}}{\text{Molar mass}}=\frac{5.15g}{242g/mol}=0.021moles[/tex]
[tex]V_s[/tex] = volume of solution = 323 ml
[tex]Molarity=\frac{0.021\times 1000}{323}=0.065M[/tex]
As 1 M of [tex]Fe(NO_3)_3[/tex] gives 3 M of [tex]NO_3^-[/tex] ions.
Thus 0.065 M of [tex]Fe(NO_3)_3[/tex] gives = [tex]\frac{3}{1}\times 0.065=0.195M[/tex] of [tex]NO_3^-[/tex] ions.
The molar concentartion of nitrate ion is 0.195.
Adding oil to a table would ___________ the friction when sliding a book across it.
Increase or decrease
Answer:
Increase
Explanation:
Hope it helps you
Answer:
Decrease
Explanation:
If the oil you're referring to is just some normal oil, it'll lessen the friction and cause it to side more smoothly
What is the poH of a
2.6 x 10-6 M H+ solution?
pOH = [?]
Answer:
pOH = 8.41
Explanation:
From the question given above, we obtained the following information:
Concentration of Hydrogen ion [H⁺] = 2.6×10¯⁶ M
pOH =?
Next, we shall determine the pH of the solution. This can be obtained as follow:
Concentration of Hydrogen ion [H⁺] = 2.6×10¯⁶ M
pH =?
pH = – Log [H⁺]
pH = – Log (2.6×10¯⁶)
pH = 5.59
Finally, we shall determine the pOH of the solution. This can be obtained as follow:
pH = 5.59
pOH =?
pH + pOH = 14
5.59 + pOH = 14
Collect like terms
pOH = 14 – 5.59
pOH = 8.41
Therefore, the pOH of the solution is 8.41
Answer:
8.41
Explanation:
Find the molar mass of C3H60
Answer:
The molar mass and molecular weight of C3H6O is 58.0791.
Explanation:
How many pounds of gold ore would need to be processed to obtain 5 grams of gold (Au) if the ore is 0.1% gold by mass?
Pounds of gold ore : 11,02311
Further explanationGiven
5 g of gold
0.1% gold by mass
Required
Pounds of gold ore
Solution
[tex]\tt \%mass~gold=\dfrac{mass~gold}{mass~ore}\times 100\%[/tex]
For percent mass = 0.1%, than mass of gold ore :
[tex]\tt 0.1\%=\dfrac{5~g}{mass~ore}\times 100\%\\\\mass~ore=\dfrac{5\times 100}{0.1}\\\\mass~ore=5000~g[/tex]
Conversion factor :
1 g = 0,00220462 pound, than for 5000 g = 11,02311 pounds
Measurements show that unknown compound X has the following composition: element mass % chromium 68.4% oxygen 31.5% Write the empirical chemical formula of X.
Answer: The empirical formula of X is [tex]Cr_2O_3[/tex]
Explanation:
If percentage are given then we are taking total mass is 100 grams.
So, the mass of each element is equal to the percentage given.
Mass of Cr = 68.4 g
Mass of O = 31.5 g
Step 1 : convert given masses into moles.
Moles of Cr =[tex]\frac{\text{ given mass of Cr}}{\text{ molar mass of Cr}}= \frac{68.4g}{52g/mole}=1.31moles[/tex]
Moles of O =[tex]\frac{\text{ given mass of O}}{\text{ molar mass of O}}= \frac{31.5g}{16g/mole}=1.97moles[/tex]
Step 2 : For the mole ratio, divide each value of moles by the smallest number of moles calculated.
For Cr = [tex]\frac{1.31}{1.31}=1[/tex]
For O = [tex]\frac{1.97}{1.31}=1.5[/tex]
The simple whole number ratio of Cr : O= 2: 3
Hence the empirical formula is [tex]Cr_2O_3[/tex]
Is it possible to ever separate the components of a mixture
Answer: yes they can
Explanation: Mixtures can be physically separated by using methods that use differences in physical properties to separate the components of the mixture, such as evaporation, distillation, filtration and chromatography.
Answer: A mixture is composed of two or more types of matter that can be present in varying amounts and can be physically separated by using methods that use physical properties to separate the components of the mixture, such as evaporation, distillation, filtration and chromatography.
Explanation:
Yes
at the molecular level what form of energy do the molecules have?
Answer:
kinetic energy I think so
The form of energy molecules have at the molecular level is Kinetic energy.
Kinetic energy is defined as the energy possessed by a body as a result of its motion or movement.
Molecules interact with one another through various movements that occur
within them. This happens to aid the formation of new substances in the
ecosystem. The three states of matter exhibit varying degree of movement
within its molecules.
The energy is usually in the form of chemical energy also and is the reason
why kinetic energy is the most suitable choice.
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How would a long period without sunlight affect the food web? PLEZZ HELP MEH IF YOU WANT BRAINEIST AND LIKE COMMENTED
It would cause consumers to consume more food.
It would have no effect on the food web.
It would stop decomposers from breaking down matter.
It would stop producers from producing food.
Answer:
im pretty sure its the last one
Explanation:
if plants dont have sun light they will die because the sunlight gives them the nutrients to survive
How many molecules of N2O4 are in 76.3g N2O4? The molar mass of N2O4 is 92.02 g/mol.
a. 4.59 × 10^25 N2O4 molecules
b. 5.54 × 10^25 N2O4 molecules
c. 7.26 × 10^23 N2O4 molecules
d. 1.38 × 10^24 N2O4 molecules
e. 4.99 × 10^23 N2O4 molecules
Answer:
4.99*10²³ molecules of N₂O₄ are in 76.3 g of N₂O₄
Explanation:
Avogadro's Number is the number of particles that make up a substance (usually atoms or molecules) and that can be found in the amount of one mole of said substance. Its value is 6.023*10²³ particles per mole. Avogadro's number represents a quantity without an associated physical dimension. Avogadro's number applies to any substance.
You know that the molar mass of N₂O₄ is 92.02 g/mol, and you have 76.3 g. Then you can apply the following rule of three: 92.02 grams are present in 1 mole of the compound, 76.3 grams in how many moles are they?
[tex]amount of moles= \frac{76.3 grams*1 mole}{92.02 grams}[/tex]
amount of moles= 0.83 moles
Then, you can apply another rule of three: if by definition of Avogadro's number 1 mole of the compound has 6.023*10²³ molecules, 0.83 moles of the compound, how many molecules will it have?
[tex]amount of molecules= \frac{0.83 moles*6.023*10^{23}molecules }{1 mole}[/tex]
amount of molecules= 4.99*10²³
4.99*10²³ molecules of N₂O₄ are in 76.3 g of N₂O₄
12-How many elements are in the mixture pictured below?
A-7
O B-4
C-3
D-2
In the image shown above, there are 3 elements (option C).
What is an element?Element is one of the simplest chemical substances that cannot be decomposed in a chemical reaction or by any chemical means and made up of atoms all having the same number of protons.
As stated above, all elements are made up of backbone structures called atoms. The atoms of an element are the same.
According to this question, an image is given showing atoms of different colors. Each atom with the same color belongs to a single element.
Since there are there colors, this means that there are three elements in the picture.
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Write down the possible types of atomic
Orbitals of n=4
Answer:
2
Explanation:
because first shell ( k shell ) needs only 2 electron to complete its octet .
hope it helps
how is she ddv hbggobyg khggub
When iron is combined with copper (1) nitrate, it produces iron (II) nitrate and
copper. Which of the following could NOT be a mole ratio in this chemical
reaction?
A)1 mole Fe / 2 mole Cu
B)1 mole Fe(NO3)2 / 2 mole Cu
C)2 mole Cu(NO3)2 / 2 mole Fe
D)1 mole Fe(NO3)2 / 1 mole Fe
Answer:
C)2 mole Cu(NO3)2 / 2 mole Fe
Explanation:
I'm pretty sure.
When iron is combined with copper (1) nitrate, it produces iron (II) nitrate and copper. The following could NOT be a mole ratio in this chemical reaction is:
D) 1 mole Fe(NO₃)₂ / 1 mole Fe
To determine which of the given mole ratios could NOT be part of the chemical reaction between iron and copper(1) nitrate, we need to write the balanced chemical equation for the reaction and then compare it to the given ratios.
The balanced chemical equation for the reaction is:
Fe + Cu(NO₃)₂ → Fe(NO₃)₂ + Cu
A) 1 mole Fe / 2 mole Cu
This mole ratio is consistent with the balanced chemical equation, where 1 mole of Fe reacts with 2 moles of Cu(NO₃)₂ to produce 1 mole of Fe(NO₃)₂ and 1 mole of Cu. So, this ratio could be part of the chemical reaction.
B) 1 mole Fe(NO₃)₂ / 2 mole Cu
This mole ratio is also consistent with the balanced chemical equation, where 1 mole of Fe(NO₃)₂ is produced by reacting 2 moles of Cu(NO₃)₂. So, this ratio could be part of the chemical reaction.
C) 2 mole Cu(NO₃)₂ / 2 mole Fe
This mole ratio is consistent with the balanced chemical equation, where 2 moles of Cu(NO₃)₂ react to produce 2 moles of Fe(NO₃)₂. So, this ratio could be part of the chemical reaction.
D) 1 mole Fe(NO₃)₂ / 1 mole Fe
This mole ratio implies that 1 mole of Fe(NO₃)₂ is produced by reacting with 1 mole of Fe, which is not consistent with the balanced chemical equation. The equation shows that 1 mole of Fe reacts with 1 mole of Cu(NO₃)₂ to produce 1 mole of Fe(NO₃)₂ and 1 mole of Cu. Therefore, this ratio could NOT be part of the chemical reaction.
So, the correct answer is:
D) 1 mole Fe(NO₃)₂ / 1 mole Fe
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How many bonding and non-bonding electron pairs are found in the BF3 molecule?
Answer:
MARK AS BRAINLIEST
Explanation:
Boron trifluoride only has six valence electrons and is one of the relatively rare second period covalent molecules that disobeys the octet rule. There are three bonded groups and so no lone pairs. Six electrons implies three electron pairs and therefore a trigonal geometry.
3 bonding and 0 non-bonding electron pairs are found in the BF3 molecule.
What is bonding?Chemical Bonding refers to the formation of a chemical bond between two or more atoms, molecules, or ions to give rise to a chemical compound.
Boron trifluoride only has six valence electrons and is one of the relatively rare second-period covalent molecules that disobeys the octet rule.
There are three bonded groups and so no lone pairs. Six electrons imply three electron pairs and therefore a trigonal geometry.
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What causes the moon to be illuminated?
A. concave
B. reflection
C. medium
D. refraction
Answer:
Reflection
Explanation:
The light from Earth's surface, reflected back towards the Moon, can illuminate it all the same. This is why, when the Moon is in a crescent phase, you can still see features on the dark portion of the Moon: we call this reflected, illuminating light the phenomenon of Earthshine.
Which of the following is/are true regarding initial and maximal velocity of enzyme-mediated reactions?
a. At very low substrate concentrations, the initial velocity of an enzyme reaction will be lower than the maximal velocity of the enzyme reaction.
b. When an enzyme behaves with Michaelis-Menten kinetics, the initial velocity of that enzyme reaction changes with substrate concentration, but the maximal velocity of that particular enzyme remains the same at a constant enzyme concentration and identical reaction conditions
c. Initial velocity is maintained until maximal velocity is reached.
d. The initial velocity is determined by the slope of the line at the beginning of a reaction when one plots the experimental results of reaction time versus product formed. Maximal velocity is then determined by when the initial velocity no longer significantly changes with increasing substrate concentration.
Answer:
a. True
b. True
c. False
d. True
Explanation:
a). A a very low substrate concentration , [tex]$S<< Km$[/tex]. Thus according to the Machaelis-Menten equation becomes
[tex]$V_0 = \frac{V_{max} \times [S]}{Km}$[/tex]
Here since the [tex]$V_0$[/tex] varies directly to the substrate concentration [S], the initial velocity is lower than the maximal velocity. Thus option (a) is true.
b). The Michaelis -Menten kinetics equation states that :
[tex]$V_0 = \frac{V_{max} \times [S]}{Km+[S]}$[/tex]
Here the initial velocity changes directly with the substrate concentration as [tex]$V_0$[/tex] is directly proportional to [S]. But [tex]$V_{max}$[/tex] is same for any particular concentration of the enzymes. Thus, option (b) is true.
c). As the substrate concentration increases, the initial velocity also increases. Thus option (c) is false.
d). Option (d) explains the procedures to estimate the initial velocity which is correct. Thus, option (d) is true.
How many milliliters of 60% carbonic acid must be mixed with how many milliliters of 15% carbonic acid to make 650 milliliters of a 38% carbonic acid solution
Answer:
348.9 mL of the 60% solution and 251.1 mL of the 15% solution.
Explanation:
First, we calculate how many mililiters of pure carbonic acid are there in 650 mL of a 38% solution:
650 mL * 38/100 = 247 mLThen we can express the sum of both initial solutions as:
1) x * 60/100 + y * 15/100 = 247for the volume of carbonic acid; and
2) x + y = 600 mLFor the volume of the solutions.
We now have a system of two equations and two unknowns (x is the volume of the 60% solution and y is the volume of the 15% solution).
We express x in terms of y in equation 2):
x = 600 - yAnd replace x in equation 1):
(600 - y) * 60/100 + y * 15/100 = 247360 - 0.6y + 0.15y = 247-0.45y = -113y = 251. 1 mLFinally we calculate x using equation 2):
x + 251.1 = 600x = 348.9 mLHow does energy from Earth’s interior affect surface changes?
Answer:
Energy produced deep inside Earth heats rock in the mantle. ... As it becomes less dense, the heated rock rises toward Earth's surface. The cooler, denser rock surrounding the heated rock sinks, as Figure 5 shows. In this way, heat inside Earth moves toward the cooler crust.
Explanation:
do you like my og name
Energy from Earth’s interior affect surface changes due to:
Earth heat transport occurs by conduction, mantle convection, hydrothermal convection, and volcanic advection. Thus, about 99% of Earth's internal heat loss at the surface is by conduction through the crust, and mantle convection is the dominant control on heat transport from deep within the Earth.Tectonic processes and flow in Earth's interior drive deformation of Earth's surface that can lead to destructive earthquakes, tsunamis, and volcanic eruptions.Learn more:
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PlEasE help ASAP
Snskskssmskssm
Answer:
message me on messenger johnpatrick so I can help you
4. On the island of Hawaii, Keanu notices that the sand on the beach is black, the same color as the
rock formations on the island. Keanu realizes the sand used to be part of the rock formations. How
did material from the rock formations turn into sand?
Answer:
The ricks were degraded over time by wind and water and were crushed down into tiny, smaller rocks, which is sand.
Explanation:
This is my first answer sorry im not that smart
A compound is found to contain 2.270 % hydrogen, 34.80 % phosphorus, and 62.93 % oxygen by mass. What is the empirical formula for this compound
Answer: The empirical formula is [tex]H_4P_2O_7[/tex]
Explanation:
If percentage are given then we are taking total mass is 100 grams.
So, the mass of each element is equal to the percentage given.
Mass of H= 2.270 g
Mass of P = 34.80 g
Mass of O = 62.93 g
Step 1 : convert given masses into moles
Moles of H = [tex]\frac{\text {given mass}}{\text {Molar mass}}=\frac{2.270g}{1g/mol}=2.270[/tex]
Moles of P = [tex]\frac{\text {given mass}}{\text {Molar mass}}=\frac{34.80g}{31g/mol}=1.122[/tex]
Moles of O = [tex]\frac{\text {given mass}}{\text {Molar mass}}=\frac{62.93g}{16g/mol}=3.933[/tex]
Step 2 : For the mole ratio, divide each value of moles by the smallest number of moles calculated.
For H = [tex]\frac{2.270}{1.122}=2[/tex]
For P= [tex]\frac{1.122}{1.122}=1[/tex]
For O = [tex]\frac{3.933}{1.122}=3.5[/tex]
The simples ratio will be = H: P : O= 4: 2: 7
Hence the empirical formula is [tex]H_4P_2O_7[/tex]
A compound is found to contain 64.80 % carbon, 13.62 % hydrogen, and 21.58 % oxygen by weight. To answer the questions, enter the elements in the order presented above. 1. What is the empirical formula for this compound
Answer:
[tex]C_{4}H_{10}O[/tex]
Explanation:
Hello!
In this case, since the empirical formula of compounds whose by-mass compositions are known, is computed by first computing the moles considering those compositions as actual masses:
[tex]n_C=\frac{64.82g}{12.01g/mol}=5.40mol\\\\n_H=\frac{13.62g}{1.01g/mol}=13.5mol\\\\n_O=\frac{21.58g}{16g/mol}=1.35mol[/tex]
Next, we divide each moles by the fewest ones, in this case those of oxygen to obtain the subscript in the empirical formula:
[tex]C=\frac{5.40}{1.35}= 4\\\\H=\frac{13.5}{1.35}=10\\\\O=\frac{1.35}{1.35}=1[/tex]
Thus, we obtain:
[tex]C_{4}H_{10}O[/tex]
Best regards
curicun, named for marie curie, has approximately 25 different isotopes that emit an alpha particle when their nuclei decay. if curium-247, the most abundant nuclide, emit and alpha particle, what daughter nuclide is formed?
A. Californium-251
B. Plutonium-243
C. Californium-249
D. Plutonium-251
Answer:
Option B. Plutonium-243
Explanation:
To know the the correct answer to the question, we shall write the balanced equation for the reaction showing curium-247 (²⁴⁷Cm) emitting alpha particle. This is illustrated below:
²⁴⁷₉₆Cm —> ᵐₙX + ⁴₂He
Next, we shall determine m, n and X. This can be obtained as follow:
247 = m + 4
Collect like terms
247 – 4 = m
243 = m
Thus, m is 243
96 = n + 2
Collect like terms
96 – 2 = n
94 = n
Thus, n is 94
m = 243
n = 94
ᵐₙX => ²⁴³₉₄X => ²⁴³₉₄Pu
Thus, the equation is:
²⁴⁷₉₆Cm —> ²⁴³₉₄Pu + ⁴₂He
From the illustrations above, the daughter nuclei formed is Plutonium-243 (²⁴³₉₄Pu)
Answer:
Plutonium-243
Explanation:
(5) Use scientific notation, make the following conversions:
6.20 km to m
Answer:
6200 meters
Explanation:
To convert from km to m you have to multiply the number by a thousand
Answer:
6.2×10^3 m
Explanation:
6.20×1000=6200m
In scientific notation 6200 = 6.2×10^3