Answer:
Light is made up of wavelengths of light, and each wavelength is a particular colour. The colour we see is a result of which wavelengths are reflected back to our eyes. The visible spectrum showing the wavelengths of each of the component colours. The spectrum ranges from dark red at 700 nm to violet at 400 nm.The 'colour' of an object is the wavelengths of light that it reflects. This is determined by the arrangement of electrons in the atoms of that substance that will absorb and re-emit photons of particular energies according to complicated quantum laws.The reason that different waves of light appear to be different colors of light is because the color of a light wave depends on its wavelength. For example, the wavelength of blue light is about 450 nanometers, while the wavelength of red light is about 700 nanometers.
Explanation:
Please help me complete the following word equations:) also write the balanced equation, full ionic equation, and net ionic equation. Also include the states:)
a) zinc nitrate + calcium sulphide—>
b) potassium + calcium chloride—>
Explanation:
The states may differ depending on the reactions
If 18.0 kJ of energy are applied to 250. grams of water at 37°C, what will be the final temperature
Answer:
54.1°C
Explanation:
Now we have the following parameters from the question;
Heat applied (H)= 18.0×10^3 Joules
Mass of the water(m)= 250g= 0.25Kg
Initial temperature of the water (θ1)= 37°C
Final temperature of the water (θ2)= the unknown
Heat capacity of water (c) = 4200JKg-1
From ;
H= mc(θ2-θ1)
Substituting values appropriately
18×10^3= 0.25 × 4200(θ2-37)
18×10^3 = 0.25 × (4200θ2 - 155400)
18×10^3 = 1050θ2 - 38850
18×10^3 + 38850 = 1050θ2
56850 = 1050θ2
θ2= 56850/1050
θ2= 54.1°C
Juan puts a pencil into a glass of water. The pencil appears broken at the point where it enters the water. What causes the pencil to look broken? A. The water in the glass absorbs incoming light waves so light cannot pass through the water. B. The light waves traveling through the glass are refracted as the waves pass from air to water. C. The water in the glass changes incoming light waves into a different form of energy. D. The light waves traveling through the glass are reflected by the pencil when it is underneath the water.
Answer:
d
Explanation:
A compound contains 46% Sodium, 12% Carbon and 42% Oxygen. The molecular mass of the compound is 106 u. Draft a table with these data and find the Empirical formula and Molecular formula of this compound. Given that atomic masses are Na=23 u, C=12u and O=16u.
Answer:
Empirical formula is Na₂CO₃
Molecular formula is Na₂CO₃
Explanation:
Percentage compositions of the elements;
Sodium = 46%
Carbon = 12 %
Oxygen = 42%
To determine empirical formula, we calculate the mole ratio first.
mole ratio = % mass/atomic mass; where the atomic masses of the elements are : Na = 23 u, C = 12 u and O = 16 u.
mole ratio: Na = 46/23; C = 12/12; O = 42/16
mole ratio (Na : C : O) = 2 : 1 : 2.6
approximate mole ratio = 2 : 1 :3
Therefore, empirical formula of compound is Na₂CO₃
To determine the molecular formula;
molecular formula or mass = n(empirical formula or mass)
n = molecular mass/empirical mass
molecular mass = 106 u,
empirical mass = 23*2 + 12 + 16*3 = 106 u
then, n = 106/106 = 1
therefore, molecular formula = 1 * (Na₂CO₃) = Na₂CO₃
A second - order reaction has a rate constant of 0.06 M min - 1 . It takes min for the reactant concentration to decrease from 0.13 M to 0.088 M. Select one : O a . 73.4 O b . 7.80 O c . 6.50 O d . 61.2
Answer:
Choice D. Approximately [tex]61.2[/tex] minutes.
Explanation:
The reaction rate of a second-order reaction is proportional to the square of one of its reactants.
Let [tex]y[/tex] denote the concentration of that reactant (in [tex]\rm M[/tex].)Let [tex]t[/tex] denote time (in minutes.)Let [tex]k[/tex] denote the rate constant of this reaction. Assume that [tex]y_0[/tex] is the concentration of that reactant at the beginning of this reaction (when [tex]t = 0[/tex].) Because this reaction is of second order, it can be shown that:
[tex]\displaystyle y = \frac{1}{k\, t + (1/y_0)}[/tex].
The question states that the rate constant here is [tex]0.06\; \rm M\cdot min^{-1}[/tex]. Hence, [tex]k = 0.06[/tex]. For simplicity, assume that [tex]t = 0[/tex] when the concentration is [tex]0.13\; \rm M[/tex]. Therefore, [tex]y_0 = 0.13[/tex]. The equation for concentration [tex]y[/tex] at time [tex]t[/tex] would become:
[tex]\displaystyle y = \frac{1}{\underbrace{0.06}_{k}\, t + (1/\underbrace{0.13}_{y_0})}[/tex].
The goal is to find the time at which the concentration is [tex]0.088[/tex]. That's the same as solving this equation for [tex]t[/tex], given that [tex]y = 0.088[/tex]:
[tex]\displaystyle \frac{1}{0.06\; t + (1/0.13)} = 0.088[/tex].
[tex]t \approx 61.2[/tex].
In other words, it would take approximately [tex]61.2[/tex] minutes before the concentration of this second-order reactant becomes [tex]0.088\; \rm M[/tex].
Which element is undergoing reduction?
1 Ag
2 Ag+
3 Pb
4 Pb+2
Answer:
Ag is under going reduction
Certain chemical reactions can be used as a source of direct electrical current in a device called
Answer:
A battery
Explanation:
A battery is a device which converts chemical energy into electrical energy . Most batteries operate as chemical cells. It is the redox reactions taking place inside the battery that causes electric current to flow via the terminals of the battery to an external circuit.
There are two main types of batteries, viz;
Rechargeable batteries
Non rechargeable batteries
A rechargeable battery is recharged by passing electric current in the reverse direction through the battery; it can be used multiple times to produce electricity in order to power devices. An example of a rechargeable battery is the Lithium-ion battery used in laptops and cell phones.
A non rechargeable battery will give electricity until the chemicals present it are used up(the chemical reactions producing electrical energy attain equilibrium). An example of a non rechargeable battery is a dry cell.
the solution of ash of magnisium ribbon is ____
Answer:
Alkaline
Explanation:
The solution of ash of magnesium ribbon is alkaline.
how many total bonds does carbon form with oxygen in carbon dioxide?
Answer:
2 bonds
Explanation:
because carbon dioxides is CO2
the carbon bond to the oxygen
then the same carbon to another oxygen making CO2
What will it’s change in temperature be?
_______________’c?
Answer:
72.8°C
Explanation:
Step 1:
Data obtained from the question. This include the following:
Specific heat capacity (C) = 0.24J/g°C
Mass (M) = 15g
Heat (Q) = 262J
Change in temperature (ΔT) =..?
Step 2:
Determination of the change in temperature.
The change in temperature, ΔT can be obtained as follow:
Q = MCΔT
262 = 15 x 0.24 x ΔT
Divide both side by 15 x 0.24
ΔT = 262 / (15 x 0.24)
ΔT = 72.8°C
Therefore, the change in temperature, ΔT is 72.8°C
What is the density of CO2 at a pressure of 0.0079 atm and 227 K? (These are the approximate atmospheric in Mars)
Answer:
The density is 0.0187 g/L
Explanation:
First thing to do here is to calculate the Volume of 1 mole of CO2 using the ideal gas equation
Mathematically;
PV = nRT
thus V = nRT/P
what we have are;
n = 1 mole
R is the molar has constant = 0.082 L•atm•mol^-1•K^-1
P is the pressure = 0.0079 atm
T is temperature = 227 K
Substituting these values, we have;
V = nRT/P = (1 * 0.082 * 227)/0.0079
V = 2,356.20 dm^3
This means according to the parameters given in the question, the volume of 1 mole of carbon iv oxide is 2,356.20 dm^3
But this is not what we want to calculate
What we want to calculate is the density
Mathematically, we can calculate the density using the formula below;
density = molar mass/molar volume
Kindly recall that the molar mass of carbon iv oxide is 44 g/mol
Thus the density = 44/2356.20 = 0.018674136321195 which is approximately 0.0187 g/L
The pH of a solution is 2.0. Which statement is correct?
Useful formulas include [H30+1 = 1070F, FOH-7-10 +0H, PH+pOH = 14, and [H30 [0H-]- 10-14
Answer:
pH + pOH = 14, [H₃0⁺] [0H⁻] = 10⁻¹⁴
Explanation:
When it comes to questions involving pH, the equations used are;
[H₃0⁺] [0H⁻] = 10⁻¹⁴
This equation shows the concentration of hydroxonium ions alongside that of the hydroxide ions.
pH + pOH = 14
If the value of either the pH of the pOH is know,one can calculate the value of the other using this equation.
Answer:
The answer is A. The pOH of the solution is 12.0
Explanation:
The formula for pOH is:
pOH = 14 - pH
We know that the pH value is 2.0 so we plug it in the equation:
pOH = 14 - (2.0)
After simplifying it, we get an answer of 12.0 which is the pOH value.
Hope this helps!
Which are the reactants in the following reaction?
2 Mg + O2 ---> 2MgO
a)Mg and O
b)Mg and MgO
c)MgO
d)O and MgO
Answer:
The second one is correct
Explanation:
Because reactants are sth that attend in a reaction and can make sth like (MgO) of course in this question. For example in this reaction : H+ClHCl. That H and Cl are reactants
Good luck
You can bake food in either a metal pan or an oven safe glass. Which would require more energy to heat up? Which would cool down the fastest? Explain your reasoning.
The kind of material used to bake food will influence how much energy is required to heat it up and how quickly it cools. Due to the fact that metal conducts heat more effectively than glass, heating up metal pans often takes longer than heating up glass ovenware.
What is the behavior of metal with the heat ?This implies that the metal absorbs heat from the oven more rapidly and effectively, needing more energy to attain the appropriate temperature. However, oven-safe glass will cool down more quickly than metal.
This is due to the fact that glass is a poor heat conductor, which means it takes more time for the heat to be absorbed by the glass. The glass will shatter after the dish is cooked and the heat is turned off.As the heat takes longer to dissipate, the metal cools down more quickly than the other materials.
In conclusion, glass cools more quickly than metal and requires less energy to heat up than oven-safe metal. This is because metal absorbs heat from the oven more rapidly and effectively than glass since metal is a stronger heat conductor than glass.
However, because glass is a poor conductor of heat, it takes longer for the food to cook and the heat to be absorbed. The glass cools down more quickly than the metal when the heat is gone.
Learn more about conductor at:
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A 18 g sample of metal is heated to 96°C and placed in a calorimeter containing 21 g of water at an initial temperature of 24°C. After the metal cools in the water bath, the final temperature inside the calorimeter is 26°C. What is the (positive) specific heat of the metal rounded to the HUNDREDTHS place? (hint: final temperatures of metal and water are the same).
Answer:
THE SPECIFIC HEAT OF THE METAL IS 0.14 J/g K
Explanation:
First, write out the variables in the question
Mass of sample = 18 g
Initial temp of metal = 96°C = 96 + 273 = 369 K
Mass of water = 21 g
Initill temp of water = 24°C = 24 + 273 K = 297 K
final temp of water and metal = 26°C = 26 + 273 K = 299 K
temperature change = (
In calorimetry, there is conservation of energy and heat liberated by one is absorbed by the other. That is heat gained is equals to heat lost.
Heat lost by the metal = Heat gained by water
mc ΔT = mc ΔT
18 * C * ( 299 - 369 ) = 21 * 4.2 * ( 299 - 297)
18 * C * -70 = 21 * 4.2 * 2
-1260 C = 176.4
C = 176.4 / 1260
C = 0.14 J/ g K
The specific heat of the metal is hence 0.14 J/g K
Give one possible explanation for the car’s distance from the starting location at 9:00 a.m. and at 9:30 a.m.
Answer:
Temporary road closure or coffee break
Explanation:
Assume a car started on a trip at 08:00 and the graph below shows the total distance it travelled every half-hour.
We see that after 1 h (at 09:00) the car was a certain distance from the start.
A half-hour later (at 09:30) the car was still at the same distance.
The car was stopped.
There may have been a bad traffic accident that closed the road or the driver may have stopped for a quick cup of coffee.
Which of the following is included in the measure of U.S. GDP?
the value of increase in business inventories.
The combustion of hydrogen and oxygen is commonly used to
power rocket engines:
2H2 (g) + O2 (g) → 2H20 (g)
If the final pressure of water vapor was 0.875 atm and the
temperature is 400. K, how many mols of H2O was produced
assuming that the reaction went to completion in a 250.L
engine?
mol
Answer:
6.66 mol
Explanation:
(atm x L) ÷ (0.0821 x K)
(0.875 x 250) ÷ (0.0821 x 400)
=6.66108
The Kelvin temperature of sample of 650 cm sample of ammonia gas is doubled what is the new volume of the gas
Answer:
1300cm3.
Explanation:
Step 1:
Data obtained from the question.
Initial temperature (T1) = K
Initial volume (V1) = 650 cm3
Final temperature (T2) = double the original = 2K
Final volume (V2) =..?
Step 2:
Determination of the new volume of the gas.
The new volume of the gas can be obtained by using Charles' law as follow:
V1/T1 = V2/T2
650/K = V2/2K
Cross multiply
K x V2 = 650 x 2K
Divide both side by K
V2 = 650 x 2K /K
V2 = 650 x 2
V2 = 1300cm3.
Therefore, the new volume of the gas is 1300cm3
The new volume of the gas is 1300cm³.
Calculation for volume:Given:
Initial temperature (T₁) = K
Initial volume (V₁) = 650 cm3
Final temperature (T₂) = double the original = 2K
To find:
Final volume (V₂) =?
Determination of new volume:
V₁/T₁ = V₂/T₂
650/K = V₂/2K
K x V₂ = 650 x 2K
V₂ = 650 x 2K /K
V₂ = 650 x 2
V₂ = 1300cm³
Therefore, the new volume of the gas is 1300cm³.
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An object has a mass of 10 kg. when a net force of 40 n north acts on the object, what is it’s acceleration ?
Answer:
4m/s² north.
Explanation:
Data obtained from the question include the following:
Mass (m) = 10Kg
Force (F) = 40N North.
Acceleration (a) =...?
Force is simply the product of mass and acceleration. It is represented mathematically as:
Force (F) = Mass (m) x acceleration (a)
F = ma
With the above formula, we can obtain the acceleration of the object as follow:
40 = 10 x a
Divide both side by 10
a = 40/10
a = 4m/s²
Since the force was applied in the north direction, the object will also accelerate in the north direction. Therefore, the acceleration of the object is 4m/s² north.
Find the valance shell and valance electron nitrogen
Answer:
The number of valence electrons is the number of electrons in the outer shell, that the atom uses for bonding. Nitrogen has 5 electrons in its n=2 (outer) shell. There is a quick way of identifying the number of valence electrons - it is the same as the Group number.
Explanation:
what is the law of conversation of mass
Answer:
Law of conversation of mass
Explanation:
According to the law of conservation of mass, mass cannot be made or destroyed. The energy can only be transferred from one state of matter to another. When the mass is changed from one state of matter to another, the mass is rearranged and changed but is not destroyed. Thus it can be concluded that during a chemical reaction, the mass of the reactants and the products remain the same.
What is the general formula for the homologous series that includes ethene?
Answer:
See below
Explanation:
The common formula of the same alkene series is CnH2n, where n is the quantity of atoms of carbon. Owing to the hydrocarbons of alkenes with at least one double carbon relation, the alkene-like sequence starts with ethen C2H4.
Hope this helps.
The general formula for the homologous series which includes ethene is alkenes.
Alkenes
They are homologous series with the general formula CxH2x.
Where:
x = number of carbon atoms.
Examples are methene with one carbon atom: CH2
Ethene with 2 carbon atoms: C2H4
Propene with 3 carbon atoms: C3H6
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Which is more reactive: Magnesium or Potassium?
Which factor(s) will most likely lower the activation energy of a reaction?
A. Concentration
B. Temperature and Concentration
C. Catalysts
D. Temperature and Catalysts
TRUE OR FALSE
Measurement of the position and velocity of a particle cannot be measured simultaneously with the same precision and accuracy.
Answer:
True.
Explanation:
To describe the problem of trying to locate a subatomic particle that behaves like a wave, Werner Heisenberg formulated what is now known as the Heisenberg uncertainty principle: it is impossible to know simultaneously both the momentum p (defined as mass times velocity) and the position of a particle with certainty.
Making measurement of the momentum of a particle more precise means that the position must become correspondingly less precise. Similarly, if the position of the particle is known more precisely, its momentum measurement must become less precise.
Which change will always result in an increase in the
avitational force between two objects?
increasing the masses of the objects and increasing the distance between the objects
decreasing the masses of the objects and decreasing the distance between the objects
O increasing the masses of the objects and decreasing the distance between the objects
O decreasing the masses of the objects and increasing the distance between the objects
Answer:
the third option:
increasing the masses of the objects and decreasing the distance between the objects
what is the symbol for sodium chloride?
what is ⅓ of 21
answer me this please
Answer:
7
Explanation:
1/3 of 21 is also the same as 21/3, which is 21 divided by 3
So the right answer is 7.
please see attached picture for full solution
hope it helps
Good luck on your assignment
How can a chemical reaction be sped up? Select from the drop-down menu to correctly complete the statement. Expose more of the reactant by increasing the
Answer:
I think the answer is Temperature but i don't know your options so I'm just going off of my test
Explanation:
