Answer:
As the police car moves towards them, the pitch of the police car's siren goes up because the sound waves get closer together in front of the police car. When the police car moves away from the person, the pitch goes down because the waves spread out behind the police and that makes the frequency go down.
Explanation:
iron is a :
A. substance
B. heterogenous mixture
C. homogenous mixture
Answer:
a: iron is a substance
Explanation:
because its hard and brittle and classified as a metal
The technology in the picture produces which energy conversion?
O A. Chemical energy to kinetic energy
O B. Kinetic energy to electrical energy
O c. Thermal energy to kinetic energy
D. Light energy to electrical energy
Answer:
Its D. Light energy to to electrical energy
Explanation:
Answer:
D. Light energy to electrical energy
Explanation:
its lowkey obvious lol
What is the number of protons for the following?
190
+2
Os
76
Answer:
190+2=192
Explanation:
192 add it 192 added
Answer: they are right
Explanation:
what is the relationship between kinetic energy and velocity ?
I am in the second period and belong to the same family as silicon
Answer:
carbon
Explanation:
carbon has 6e- hence belong to group 4 and period 2
Answer:
Boron
Explanation:
Both silicon and boron are metalloids, and boron belongs on the second row (period)
a balanced chemical equation is an equation which shows that the total mass is conserved during a chemical reaction. Which of the following chemical equation agree with the statement. 1)Na+Cl2=NaCl 2)Na+H2O=NaOH+H2 3)C+O2=CO2 4)CaCO3=CaO+CO2.
Answer:
c )C02
d)CaO + CO2
Explanation:
the masses of the elements are conserved
In the reaction given below, 23.5 grams of iron(III) oxide (Fe2O3) are reacted with excess carbon. What is the theoretical yield of iron metal?
2 Fe2O3 + 3 C --> 4 Fe + 3 CO2
If 14.5 grams of iron are recovered when the reaction is complete, what is the percent yield?
**Both answer should be written as XX.X
Answer:
Theoretical yield = 16.76 g
Percent yield = 87%
Explanation:
Given data:
Mass of iron oxide = 23.5 g
Theoretical yield of iron = ?
Actual yield of iron = 14.5 g
Percent yield of iron = ?
Solution:
Chemical equation:
2Fe₂O₃ + 3C → 4Fe + 3CO₂
Number of moles of iron oxide:
Number of moles = mass/molar mass
Number of moles = 23.5 g/ 159.69 g/mol
Number of moles = 0.15 mol
Now we will compare the mole of iron oxide with iron metal.
Fe₂O₃ : Fe
2 : 4
0.15 : 4/2×0.15 = 0.3
Mass of iron:
Mass = number of moles × molar mass
Mass = 0.3 mol × 55.85 g/mol
Mass = 16.76 g
Percent yield:
percent yield = (actual yield / theoretical yield)× 100
Percent yield = (14.5 g / 16.76 g) × 100
Percent yield = 0.87 × 100
Percent yield = 87%
Answer:
I tried the answer above and it’s correct
Explanation:
A student was traveling to see his grandmother who lives 15 miles north of his home. He started from rest and maintained a pace of 4 m/s before stopping at his grandmother’s house for lunch. (8.6B) Which of the following best describes the speed, velocity, and acceleration of the student’s walk?
Answer:
He traveled at a speed of 4 m/s with a velocity of 4m/s north, and his acceleration changed when stopping for lunch.
Explanation:
Trust me took test got it right!
What is the charge on a calcium atom that contains 18e−?
Answer:
13 +2 =15
Explanation:
A student asks a serious of questions about a wave. The answer to which question will allow the student to determine whether the wave is electromagnetic or mechanical?
Answer:
Does the wave require a medium in order to travel?
Explanation:
The question whose answer would determine whether the wave in question is mechanical or electromagnetic would be if the wave requires a medium in order to travel or otherwise.
A mechanical wave would require a medium in order to transport its energy from one place to another, that is, travel. On the other hand, an electromagnetic wave does not require any medium in order to travel, that is, it can travel through vacuums or empty spaces. Light and sound waves are typical examples of electromagnetic and mechanical waves respectively.
A chemistry teacher is able to grade chemistry labs at a rate of 5 labs for every 3 minutes. They need to grade 165 labs how many hours will it take?
Answer:
1.65hr
Explanation:
Given parameters:
Number of labs = 5 labs
Time taken = 3 minutes
Unknown:
Time taken in hours to grade 165 labs = ?
Solution:
Let us find the rate of the teacher;
Rate = [tex]\frac{number of labs}{time}[/tex]
Insert the parameters and solve;
Rate = [tex]\frac{5}{3}[/tex] = 1.67labs/min
Now;
Time to grade 165 labs = [tex]\frac{number of labs}{rate}[/tex]
Time to grade 165 labs = [tex]\frac{165}{1.67}[/tex] = 98.8min
Since;
60min = 1hr
98.8min = [tex]\frac{98.8}{60}[/tex] = 1.65hr
Earth's atmosphere blocks short wavelengths of the electromagnetic spectrum. Which telescopes must be places in orbit around Earth in order to observe short-wavelength radiation?
Answer: gamma-ray telescopes
Explanation:
this is the answer because the question is asking what telescope must be
placed to observe SHORT-WAVELENGTH radiation. Gamma-rays have very short wave-lengths so therefore it would be gamma-ray telescopes. visible, infrared, and radio all have long wave-lengths, so we can instantly eliminate them.
The Earth's atmosphere is known to be able to blocks all X-rays from space. telescopes must be places in orbit around Earth in order to observe short-wavelength radiation is gamma-ray telescope.
X-rays is known to have high energy that are in reflecting telescope. Gamma rays from space is commonly blocked by the Earth's atmosphere as the radiation is lethal.
Gamma-ray telescope is known to be an instrument that is created to detect and resolve gamma rays from space. that is beyond Earth's atmosphere.This rays are able too be detected by the optical flashes that they emit when interacting with the material in a particular defined instrument.
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Select ALL of the following statements that are incorrect.
Solids, liquids, and gases are all able to act as solutes in a solution.
Solids, liquids, and gases are all able to act as solvents in a solution.
Solids are not able to act as a solvent if a gas is the solute.
Gases are not able to act as a solvent if a solid is the solute.
Answer:the 4th one is incorrect,and the 1st one is incorrect hope this helps.
Adsorption is defined as a process in which gas molecules tend to adsorb on the surface of a solid solvent.
Therefore, the statement solids are not able to act as a solvent if a gas is the solute, is false.
On the other hand, gases can also act as a solvent if a solid is the solute.
Explanation:
Adsorption is defined as a process in which gas molecules tend to adsorb on the surface of a solid solvent.
Therefore, the statement solids are not able to act as a solvent if a gas is the solute, is false.
On the other hand, gases can also act as a solvent if a solid is the solute.For example, air present in the surrounding acts as a solvent and solid substances present in the surrounding acts as a solute.
Hence, the statement gases are not able to act as a solvent if a solid is the solute, is false.
Thus, we can conclude that following are the statements which are incorrect.
Solids are not able to act as a solvent if a gas is the solute.
Gases are not able to act as a solvent if a solid is the solute.
Which property of waves is the distance between one point on a wave and that same point on the wave next to it?
A.
amplitude
B.
wavelength
C.
frequency
D.
speed
What do minerals do when they are heated?
what is the density of a 100g piece of titanium if a 10g piece of titanium has a density of 4.506g/cm3?
Possible answers:
A: 45.06g/cm3
B:4.506g/cm3
C: 9.1g/cm3
D: 91g/cm3
Answer:
B. Density stays the same no matter how much of a substance there is.
Explanation:
Density of the substance is the same and it is the measure of its mass per unit volume. Thus, the mass of titanium per 1 cm³ is 4.506 g which is the same for 10 g, 100 g or whatever the mass.
What is density ?Density of a substance is the measure of its mass per unit volume. It describes how closely its particles are packed. Density of an object depends on its bond type, temperature and pressure.
The more denser the object is , more will be its mass distribution per unit volume. Substances denser than water will sink on it otherwise they float on water.
Density is constant for a substance, the distribution of given mass per unit volume is same for all masses. Hence, the density of 100 g Ti is same as that of 10 g. i.e., 4.56 g/cm³.
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If 5.0 liters H2 (g) at STP is heated to a temperature of 985, pressure remaining constant, the new volume of the gas will be?
Answer:
[tex]V_2=18 \ L \ H_2[/tex]
General Formulas and Concepts:
Chemistry - Gas Laws
STP (Standard Conditions for Temperature and Pressure) = 22.4 L per mole at 1 atm, 273 KCharles' Law: [tex]\frac{V_1}{T_1} =\frac{V_2}{T_2}[/tex]Explanation:
Step 1: Define
Initial Volume: 5.0 L H₂ gas
Initial Temp: 273 K
Final Temp: 985 K
Final Volume: ?
Step 2: Solve for new volume
Substitute: [tex]\frac{5 \ L \ H_2}{273 \ K} =\frac{x \ L \ H_2}{985 \ K}[/tex]Cross-multiply: [tex](5 \ L \ H_2)(985 \ K) = (x \ L \ H_2)(273 \ K)[/tex]Multiply: [tex]4925 \ L \ H_2 \cdot K = 273x \ L \ H_2 \cdot K[/tex]Isolate x: [tex]18.0403 \ L \ H_2 = x[/tex]Rewrite: [tex]x=18.0403 \ L \ H_2[/tex]Step 3: Check
We are given 2 sig figs as the smallest. Follow sig fig rules and round.
[tex]18.0403 \ L \ H_2 \approx 18 \ L \ H_2[/tex]
what is the molecular formula of carbohydrate
Answer:
Carbohydrates can be represented by the stoichiometric formula (CH2O)n, where n is the number of carbons in the molecule. Therefore, the ratio of carbon to hydrogen to oxygen is 1:2:1 in carbohydrate molecules.
Explanation:
May I have brainliest please? :)
Answer:
(CH2O)n, where n is the number of carbons in the molecule.
Explanation:
Also remember the 1:2:1 ratio of carbon:hydrogen:oxygen
Loose sugar dissolves much faster than a sugar cube because loose sugar?
A. Has greater surface area
B. Has less kinetic energy
C. Has a higher temperature
D. Has greater surface tension
Loose sugar dissolves much faster than a sugar cube because loose sugar (a) has greater surface area.
When any solute dissolve in ground into small pieces it dissolve faster in solvent than large pieces because in small ones the large surface area is exposed into solvent.
With the greater surface area is exposer, the contact in between the solute particles and the solvent is more. this is the reason that loose sugar cube dissolve much faster than sugar cube as sugar cube has less surface area in contact with solvent.
Thus, Loose sugar dissolves much faster than a sugar cube because loose sugar (a) has greater surface area.
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Dating of rock layers which layer is the youngest f,A,s,h,b,d,c,e
Answer:
E is the anwser
Oxygen molecules come from....
air
Starches
Proteins
food
Answer:
air
Explanation:
The main source of oxygen molecules is the air around us. Air is made up of 21% of oxygen gas which is the second most abundant gas found in the atmosphere.
Starch, Proteins and food are all made up of complex organic molecules. Air is a mixture of many gases. Gaseous exchange is made possible when air supplies oxygen and takes carbon dioxide away. Oxygen is an essential gas in the metabolic process of animals.write the complete balanced equation for the decomposition of AI(CIO3)3.
Answer:
2AL(ClO3)3 → 2ALCl3 + 9O2
Explanation:
Green light has a frequency of 6.01x10^14Hz what is the wavelength
Answer:
λ = 0.5×10⁻⁶ m
Explanation:
Given data:
Frequency of light = 6.01 ×10¹⁴ Hz
Wavelength of light = ?
Solution:
Formula:
Speed of light = wavelength × frequency
Speed of light = 3×10⁸ m/s
3×10⁸ m/s = λ × 6.01 ×10¹⁴ Hz
λ = 3×10⁸ m/s / 6.01 ×10¹⁴ Hz
Hz = 1/s
λ = 0.5×10⁻⁶ m
In the reaction 2Li(s) + 2H2O(I) -> 2LiOH(aq) + H2(g), which compound is in the aqueous state?
A. Li
B. H2O
C. LiOH
B. H2
Answer:
LiOH
Explanation:
LiOH has the tag "aq" which stands for aquatic.
Our answer is LiOH.
This is due tomorrow so please help! : name a product where viscosity is important its creation or use explain why it is important
i really need help pls, will pay anything
Explanation:
For the first part,
Reaction equation:
N₂ + 3H₂ → 2NH₃
Given:
Number of moles of NH₃ = 6 moles
Unknown:
Number of moles of N₂ = ?
Solution:
N₂ + 3H₂ → 2NH₃;
From the reaction above, we solve from the known specie to the unknown. Ensure that the equation is balanced;
2 moles of NH₃ is produced from 1 mole of N₂
6 moles of NH₃ will be produced from [tex]\frac{6}{2}[/tex] mole of N₂
= 3moles of N₂
The number of moles of N₂ is 3 moles
ii.
Given parameters:
Number of moles of sulfur = 2.4moles
Molar mass of sulfur = 32.07g/mol
Unknown:
Mass of sulfur = ?
Solution:
The number of moles of any substance can be found using the expression below;
Number of moles = [tex]\frac{mass}{molar mass}[/tex]
Mass of sulfur = number of moles of sulfur x molar mass
Insert the parameters and solve;
Mass of sulfur = 2.4 x 32.07 = 76.97g
A geologist was looking at a new
mineral they found. The mineral
sample was gray, non-metallic, had
density of 3.8 g/mL, and a volume
of 48.3 mL
Of the observed properties listed
below, which is considered to be an
extensive property?
A Gray
B Metallic
C Density
D Volume
Answer:
D. Volume
Explanation:
Properties mentioned in the question;
colour = gray
Nonmetallic
Density = 3.8 g/mL
Volume = 48.3 mL
Of the mentioned, which is extensive ?
Extensive properties are those properties that are proportional to the amount of substance present.
The correct option is D. Volume. The other properties do not change with increasing or decreasing amount of the mineral
Which is the Lewis structure for H3PO4?
Answer:
There are four σ bonds and no lone pairs around phosphorous atom in the lewis structure of H3PO4 molecule. Therefore total number of VSPER pairs are four. Therefore, shape of molecule around phosphorous atom is tetrahedral.
Explanation:
There are four σ bonds and no lone pairs around phosphorous atom in the lewis structure of H3PO4 molecule. Therefore total number of VSPER pairs are four. Therefore, shape of molecule around phosphorous atom is tetrahedral.
therefore total number of vsper pairs of four. Therefore, shape of molecule around phosphorous atom is tetrahedral.
How many grams of glucose are in 4.5x1023 molecules of glucose?:
Answer:
[tex].5865 \\ \\ \\ \\ \\ \5865[/tex]
[tex] \\ \\ 5865 \inf \inft \cos( \\ \) [/tex]
your older sister has just got her driver's licence. write a paragraph in your notebook to explain what she should do to make sure she travels safely. especially whe the roads are wet and the road surface is rough in some areas and smooth in others.