Answer:
Explanation:
Tenochtitlan was located on a swampy island in Lake Texcoco in what is today south central Mexico. The Aztecs were able to settle there because no one else wanted the land. At first, it wasn't a great place to start a city, but soon the Aztecs built up islands where they could grow crops. The water also worked as a natural defense against attacks from other cities.
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The charge on a molecule with 14 electrons and 12 protons = -2
Although your question is vague a general answer is provided above
When the number of protons and the number of electrons in a molecule are equal to each other, the charge on the molecule will be neutral, this is because Electrons are negatively charged while protons are positively charged.
Therefore a molecule with 14 electrons and 12 protons will have a charge of
= -14 + 12 = - 2
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True or False When one side of a molecule is electronegative (δ-) and the other side of the
molecule is electropositive (δ+), it is said to have a dipole moment. Water has
a dipole moment.
Answer:
True; When one side of a molecule is electronegative (δ-) and the other side of the
molecule is electropositive (δ+), it is said to have a dipole moment.
Explanation:
A dipole moment exists in a molecule as a result of differences in the electronegativity values between the atoms of the elements involved in the chemical bonding.
When a strogly electronegative atom such as oxygen or chlorine is chemically bonded to a less electronegative or an electropositive atom such as hydrogen, there is an uneven sharing of the electrons involved in the bonding. The more electronegative atoms tends to draw the shared electrons mostly to themselves. This induces a partially negative charge (δ-) on them while leaving the electropositive atoms with a partially positive charge (δ+).
Water is an example of a molecule having a dipole moment. The oxygen atoms are more electronegative than hydrogen and as such draw the shared electrons to themselves more, inducing a partial positive charge (δ+) on the hydrogen atoms while they themselves develop a partial negative charge (δ-).
Which substance can be identified as a homogeneous mixture?
chocolate milk
pepperoni pizza
chocolate chip cookie
peanut butter sandwich
Answer:
A) Chocolate Milk
Explanation:
A homogeneous mixture is one that is made of one substance. Technically, none of these are, but chocolate milk would be the closest. Pizza has cheese, pepperoni, and crust. Chocolate chip cookies have chips and the cookie. Peanut butter sandwiches have peanut butter and bread. Therefore, chocolate milk is right, as it has no other parts.
Which choice describes the function of the pancreas gland?
A. It secretes hormones that regulate blood sugar levels.
B. It secretes adrenaline to help the body respond to fear.
C. It secretes hormones that regulate water concentration levels.
D. It secretes thyroxine, which is involved in growth.
Answer:
A. It secretes hormones that regulate blood sugar levels.
Explanation:
The pancreas is the organ that helps in the process of digestion of the food. The location of the pancreas is in the abdomen. It helps in the process of digestion of the food and regulating the blood sugar level in the body. It helps in regulating and controlling the glucose level in the body during the process of digestion. Pancreas produces enzymes that are useful in the process of digestion.
Answer:
A
Explanation:
Name one trend observable in a periodic table
Answer:
Major periodic trends include: electronegativity, ionization energy, electron affinity, atomic radius, melting point, and metallic character.
Explanation:
These six are the major trends.
When looking across the periodic table from left to right, which of these groups are the first to contain nonmetals?
group 2
group 7
group 14
group 18
Answer:
The first group to contain a non-metal is Group 18.
A reaction that produces great heat for welding and incendiary bombs
is the "thermite" reaction, Fe2O3 (s) + 2Al(s) Al2O3 (s) + 2Fe (s)
How many moles of iron form by the complete reaction of
7.1 9 of iron (III) oxide ?
Answer:
7.19 g of Fe2O3 will produce 0.092 mole of iron
Explanation:
One mole of Fe2O3 reacts with 2 mole of Aluminum to produce one mole of Al2O3 and 2 mole of iron.
Mass of one mole of Fe2O3 = 159.69 g/mol
Thus, 159.69 g/mol of Fe2O3 produces two mole of Fe
7.19 g of Fe2O3 will produce
[tex]\frac{2}{156.9} * 7.19\\= 0.092[/tex]moles of iron
Phosphorus (P4) and hydrogen gas can combine to form phosphine (PH3), a toxic gas with the odor of rotting fish. Complete and balance the equation for this chemical reaction.
Answer:
P₄ + 6 H₂ ⇒ 4 PH₃
Explanation:
Let's consider the unbalanced reaction that takes place when phosphorus reacts with hydrogen to form phosphine. This is a synthesis reaction.
P₄ + H₂ ⇒ PH₃
We will balance this reaction using the trial and error method. First, we will balance P atoms by multiplying PH₃ by 4.
P₄ + H₂ ⇒ 4 PH₃
Finally, we get the balanced equation by multiplying H₂ by 6.
P₄ + 6 H₂ ⇒ 4 PH₃
How many moles are in 60.05 g of carbon
Answer:
moles =60.05/12
moles=5.0041
moles=5(approx)
You can find the speed on a distance-versus-time graph by finding the slope of the line.
True
False
Consider an electron with charge −e−e and mass mmm orbiting in a circle around a hydrogen nucleus (a single proton) with charge +e+e. In the classical model, the electron orbits around the nucleus, being held in orbit by the electromagnetic interaction between itself and the protons in the nucleus, much like planets orbit around the sun, being held in orbit by their gravitational interaction. When the electron is in a circular orbit, it must meet the condition for circular motion: The magnitude of the net force toward the center, FcFcF_c, is equal to mv2/rmv2/r. Given these two pieces of information, deduce the velocity vvv of the electron as it orbits around the nucleus. Express your answer in terms of eee, mmm, rrr, and ϵ0ϵ0epsilon_0, the permittivity of free space.
Answer:
Explanation:
The net force on electron is electrostatic force between electron and proton in the nucleus .
Fc = [tex]\frac{1}{4\pi\epsilon} \times \frac{e\times e}{r^2}[/tex]
This provides the centripetal force for the circular path of electron around the nucleus .
Centripetal force required = [tex]\frac{m\times v^2}{r}[/tex]
So
[tex]\frac{m\times v^2}{r}=\frac{1}{4\pi\epsilon} \times \frac{e\times e}{r^2}[/tex]
[tex]v^2=\frac{e^2}{4\pi \epsilon m r}[/tex]
[tex]v=(\frac{e^2}{4\pi \epsilon m r})^{\frac{1}{2} }[/tex]
When does surface water become
groundwater?
Answer:
When it rains or snows. Basically as soon as it hits the ground.
Explanation:
Groundwater begins as rain or snow that falls to the ground. This is called precipitation but only a small portion of this precipitation will become groundwater
Definition: These are the layers of rock or soil that are distinguishable from other layers that have been
laid down upon one another over the history of the earth.
01)
Term: Type term here
Strata are the layers of rock or soil that are distinguishable from other layers that have been laid down upon one another over the history of the earth.
What is a Strata?A strata is the horizontal layer of rocks or sedimentary rocks that are laid upon another or arranged one on top of another that is separated by adjacent beds planes or layers.
Therefore, Strata are the layers of rock or soil that are distinguishable from other layers that have beenlaid down upon one another over the history of the earth.
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b. What three products are necessary in order for a hydrocarbon combustion reaction to take place?
Explanation:
Description. Regardless of the type of hydrocarbon, combustion with oxygen produces 3 products: carbon dioxide, water and heat, as shown in the general reaction below.
If oxygen gas at 118 °C and 10.8 atm was heated to 948 °C, what would the new
pressure be?
Answer: The new pressure is 1.34 atm.
Explanation:
Given: [tex]P_{1}[/tex] = 10.8 atm, [tex]T_{1} = 118^{o}C[/tex]
[tex]P_{2}[/tex] = ?, [tex]T_{2} = 948^{o}C[/tex]
Formula used to calculate the new pressure is as follows.
[tex]\frac{P_{1}}{T_{1}} = \frac{P_{2}}{T_{2}}\\\frac{10.8 atm}{118^{o}C} = \frac{P_{2}}{948^{o}C}\\P_{2} = 1.34 atm[/tex]
Thu, we can conclude that the new pressure is 1.34 atm.
Which equation represents a transmutation?
Answer:
A
Explanation:
edge21
Plz help plz help me will mark Brainly
Answer:
Greenhouse gases absorb some of the energy and trap it in the lower atmosphere. Less heat radiates into space, and Earth is warmer. Many greenhouse gases occur naturally. Carbon dioxide, methane, water vapor, and nitrous oxide are naturally present in Earth's atmosphere. Since some of the extra energy from a warmer atmosphere radiates back down to the surface, Earth's surface temperature rises.
Hope this helped! :)
Determine the type of reaction: AgNO3 + Cu --> Cu(NO3)2 + Ag
Explanation:
Cu + 2 AgNO3 → Cu(NO3)2 + 2 Ag
Cu is oxidized
Ag+ is reduced
Cu is the reducing agent
To solve such this we must know the concept of displacement reaction. The balanced reaction of silver nitrate with copper is of displacement type of reaction.
AgNO[tex]_3[/tex] + Cu [tex]\rightarrow[/tex] Cu(NO[tex]_3[/tex])[tex]_2[/tex] + Ag
What is Balanced equation?Balanced equation is the one in which the total number of atoms of a species on reactant side is equal to the total number of atoms on product side. The mass of the overall reaction should be conserved. There are so many types of chemical reaction reaction like combination reaction, displacement reaction.
The reaction between silver nitrate and copper is example of displacement reaction. Copper displaces silver from silver nitrate. to form copper nitrate.
Therefore, the balanced equation is of displacement type of reaction.
AgNO[tex]_3[/tex] + Cu [tex]\rightarrow[/tex] Cu(NO[tex]_3[/tex])[tex]_2[/tex] + Ag
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A mountaineer is climbing a very tall mountain. She has bottled oxygen (oxygen gas in a rigid, metal cylinder) with her, and she breathes the oxygen on the ascent. At the summit, she stops breathing the bottled oxygen and descends safely to the base of the mountain. The temperature on the summit is –15°C, and the temperature at the base is 20°C. Describe how the change in temperature and the change in the amount of gas in the oxygen cylinder affect the pressure of the gas inside the cylinder during the ascent and descent of the mountain
Answer:
When the temperature and the amount of gas decrease, the pressure decreases.
Explanation:
At the base of the mountain, the temperature is 20 °C (293 K) and as she climbs, the temperature on the summit decreases to -15 °C (258 K). We can see the effect of the temperature on the pressure using Gay-Lussac's law.
P/T = k
P = k × T
As we can see, there is a direct relationship between P and T. So, when the temperature decreases, the kinetic energy of the gas does as well, and consequently, the pressure decreases.
Also, as the mountaineer consumes oxygen, the number of moles (n) of oxygen decreases. We can appreciate the effect on the pressure using the gas ideal equation.
P × V = n × R × T
P = n × R × T / V
There is also a direct relationship between n and P. When the amount of gas decreases, so does the pressure.
A sample of ideal gas at room temperature occupies a volume of 10.0 L at a pressure of 302 torr. If the pressure changes to 1510 torr
with no change in the temperature or moles of gas, what is the new volume, V2?
Explanation:
boyles law; P1V1=P2V2
302×10=1510×V2
V2=2L
Hi, what are you doing?
Answer:
i am dancing and you ok hom
how many moles are in 89 grams of Pb(CH3COO)4
Answer:
0.20 moles of Pb(CH3COO)4
Explanation:
89g Pb(CH3COO)4 x 1 mol Pb(CH3COO)4 / 443.376 g Pb(CH3COO)4
= 0.20 moles of Pb(CH3COO)4
One mole of lead acetate weighs 443.29 g. Then, 89 grams of lead acetate contains 0.20 moles of Pb (CH₃COO)₄.
What is one mole ?One mole of a substance is its amount containing 6.02 × 10²³ atoms or molecules. This number is called Avogadro number. One mole of every elements contains Avogadro number of atoms.
Similarly one mole of every compound contains 6.02 × 10²³ molecules. The mass of one mole of compound is called its molar mass. The number of moles of the compound can be determined by dividing the given mass by molar mass.
Molar mass of lead acetate = 443.29 g/mol
given mass = 89 grams
then , no.of moles = weight/molar mass
n = 89 g/ (443.29 g/mol) = 0.20 moles
Therefore, the number of moles of Pb (CH₃COO)₄ in 89 g is 0.20 moles.
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If the molar heat of vaporization for water is 40.7 kJ/mol. What is the molar heat of condensation? HELP ME PLEASE!!!
Answer:
not sure hope you have a good day
If the molar heat of vaporization for water is 40.7 kJ/mol. -40.7 kJ/mol is the molar heat of condensation.
What is condensation?Condensation, which is the opposite of vaporization, is the transformation of matter from its gaseous state into its liquid state. The water cycle is the most frequent use of the phrase. Another way to describe it is as the transformation of water vapor into liquid water when it comes into touch with a solid, liquid, or cloud condensation nucleus in the atmosphere.
Deposition is the term for the change that occurs when the gaseous phase directly transitions into the solid phase. Condensation is started when atomic or molecule clusters of such a species form within their gaseous volume, similar to how raindrops or snowflakes form within clouds, or when their gaseous phase comes into contact with a liquid and solid surface.
molar heat of vaporization = 40.7 kJ/mol
molar heat of condensation = -40.7 kJ/mol
Therefore, if the molar heat of vaporization for water is 40.7 kJ/mol. -40.7 kJ/mol is the molar heat of condensation.
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Use the scenario to answer the following question. A group of students working in a chemistry lab are planning a procedure to neutralize 10.0mL of 5.0 M hydrochloric acid (strong acid) with 5.0 M potassium hydroxide (strong base). In their procedure they plan on adding an equal volume of the base to the acid. What would be the expected outcome of carrying out this step as planned?
a- The resulting pH will be less than 7 because potassium hydroxide is less concentrated than the hydrochloric acid.
b- The resulting pH will not be able to be determined because the concentrations of the acid and base are not the same.
c- The resulting pH will be greater than 7 because potassium hydroxide is less concentrated than the hydrochloric acid.
d- The resulting pH will be equal to 7 because a strong base will neutralize a strong acid.
Answer:
d- The resulting pH will be equal to 7 because a strong base will neutralize a strong acid.
Explanation:
The reaction between potassium hydroxide and hydrochloric acid of equal volume and equal concentration yields a solution of pH 7 at equivalence point. We must note that KOH is a strong base while HCl is a strong acid. This fact influences the pH of the system at equivalence point.
Owing to the fact that the acid is exactly neutralized by the base; at the equivalence point of such titration, it is expected that hydrogen ions(H+) and hydroxide ions (OH-) must have reacted to form water, this leads to a final pH of 7.
When considering the equilibrium between copper(I) carbonate and its aqueous ions, what could be added to solution to promote the precipitation of copper(I) carbonate
Answer:
potassium carbonate
Explanation:
Let us consider the equilibrium for the dissociation of copper I carbonate;
Cu2CO3(s)------>2Cu^+(aq) + CO3^2-(aq)
Now we need to add a substance that has a common ion with the solute. The addition of this substance will decrease the solubility of the solute thereby increasing the concentration of the promote the precipitation of copper(I) carbonate precipitate in the system.
Hence, addition of potassium carbonate promotes the precipitation of copper(I) carbonate.
the correct order of increasing ionisation energy of Na,Al,Si and Mg elements is?
Removal of an electron from stable, fully filled orbital requires more energy than removal of electron from partially filled orbital. Thus, ionisation enthalpy for Mg is greater than ionisation enthalpy for Al. So, the correct order of first ionization enthalpies is: Na<Mg>Al<Si.
The goal of this lesson is to answer the lesson
question, "What does half-life 'look like' for a
radioactive substance?" Fill in the blanks to
complete the hypothesis.
Hypothesis: If an element is radioactive, then the
fraction of radioactive atoms v remaining after
n half-life cycles should be approximately n
because...
Answer:
The half life for radioactive can be calculated as:
N /N0 = (1 /2) ^ n
n = T /T half
According to question there are n number of half life are present which would result in remaining amount of element as n.
Explanation:
Sorry if wrong
Answer:
1. atom
2. 0.5n
Explanation:
Because half of the atom's nuclei will decay during each cycle.
Which chemical equation is balanced as written?
PLS ANSWER FAST
Answer:
THERE ANSWER IS C
Explanation:
A quantity of gas was cooled from 323 K to 273 K. Express this temperature
difference in degrees Celsius and Kelvins. What do these temperatures
represent about the gas particles? Which temperature scale is a more accurate
depiction of this representation? Explain briefly.
Answer:
give more details
Explanation:
A cylinder of gas with a pressure of 8.0 atm is heated from 300. K to 600. K. What will the new pressure of the gas be?
Answer:
[tex]P_2=16atm[/tex]
Explanation:
Hello there!
In this case, according to the given information, we can infer we need to use the Gay-Lussac's equation it order to understand this pressure-temperature relationship as shown below:
[tex]\frac{P_1}{V_1}=\frac{P_2}{V_2}[/tex]
Thus, we solve for P2 and plug in P1, T1 and T2, to obtain:
[tex]P_2=\frac{P_1T_2}{T_1}\\\\P_2=\frac{8atm*600K}{300K}\\\\P_2=16atm[/tex]
Regards!
in a hypothetical element ,two energy levels are separated by an energy of 282kj mol-1 . what wavelength of light (in nma) is evolved for an electron to change between these two levels?
Answer:
7.05 × 10⁻²² nm
Explanation:
Step 1: Given and required data
Energy evolved when a mole of electrons changes between the 2 levels (E): 282 kJPlanck's constant (h): 6.63 × 10⁻³⁴ J.sSpeed of light (c): 3.00 × 10⁸ m/sStep 2: Calculate the wavelength (λ) of the light evolved
We will use Planck-Einstein's relation.
E = h × c/λ
λ = h × c/E
λ = (6.63 × 10⁻³⁴ J.s) × (3.00 × 10⁸ m/s)/(282 × 10³ J) = 7.05 × 10⁻³¹ m
We will convert λ to nm using the conversion factor 1 m = 10⁹ nm.
7.05 × 10⁻³¹ m × 10⁹ nm/1 m = 7.05 × 10⁻²² nm