Answer:
I need more context. Maybe add a picture.
Explanation:
Answer:
Crown B
Explanation:
because the density of gold is 19.3 and the density of the crown is 19.29.
If the visible light spectrum is from 400 to 700 nm, would light with an energy of 2.79 x 10^-19 J be visible with the naked eye? What is the wavelength of this light?
Answer:
713 nm. It is not visible with the naked eye.
Explanation:
Step 1: Given data
Energy of light (E): 2.79 × 10⁻¹⁹ JPlanck's constant (h): 6.63 × 10⁻³⁴ J.sSpeed of light (c): 3.00 × 10⁸ m/sWavelength (λ): ?Step 2: Calculate the wavelength of the light
We will use the Planck-Einstein equation.
E = h × c / λ
λ = h × c / E
λ = 6.63 × 10⁻³⁴ J.s × 3.00 × 10⁸ m/s / 2.79 × 10⁻¹⁹ J
λ = 7.13 × 10⁻⁷ m
Step 3: Convert "λ" to nm
We will use the relationship 1 m = 10⁹ nm.
7.13 × 10⁻⁷ m × (10⁹ nm/1 m) = 713 nm
This light is not in the 400-700 nm interval so it is not visible with the naked eye.
what happens to the temperature of the liquid in a cup of water as some of the water evaporates?
All elements in the same group
Answer:
The elements in each group have the same number of electrons in the outer orbital. Those outer electrons are also called valence electrons. They are the electrons involved in chemical bonds with other elements. Every element in the first column (group one) has one electron in its outer shell.
Explanation:
I'm not really sure what the question is but I hope this helps.
An element has 20 protons, 22 neutrons and 18 electrons. What is the charge for this ion?
PLZ HELP I'LL AWARD BRAINLIEST
Answer:
20 protons.
Explanation:
20 protons = 20 + charges
18 electrons = 18- charges.
The difference = 20 - 18 = +2
The charge for this ion is plus 2
It is a calcium ion. The element is number 20 on the periodic table.
The charge of the ion is +2
HOW TO DETERMINE THE CHARGE OF AN ION:
The charge of an ion is a function of the number of protons and electrons in the atom. An atom consists of three subatomic particles namely: neutron, proton and electron. The proton is positively charged while the electron is negatively charged. The charge of an atom is determined by subtracting the number of electrons from protons, that is;Charge = no. of protons - no. of electronsHence, if the protons in an atom is more than the electrons, the charge will be positive and vice versa. In this case, an element has 20 protons, 22 neutrons and 18 electrons.Therefore, the charge of the ion will be 20 protons - 18 electrons = +2
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. A nail is hammered into a piece of wood. *
Answer:
and now you have a nail in your wood :)
How do weathering and deposition differ? (4 points)
оа
Weathering breaks down rocks; deposition leaves them in new places.
Ob
Weathering has to do with air; deposition has to do with plants.
Ос
Weathering occurs only in summer; deposition occurs year-round.
Od
Weathering can be chemical or physical; deposition is only chemical.
Answer:
Oa. Weathering breaks down rocks; deposition leaves them in new places.
Explanation:
Did test and got it right.
Concentration data is commonly monitored during a reaction to determine the order with respect to a reactant. Consider the types of observations listed, and determine which order is likely for that reactant. Assume all other factors are held constant.
1. An increase in the concentration of the reactant in solution causes the reaction rate to increase exponentially.
a. first order
b. second order
c. zero order
2. The reaction rate increases in direct proportion to the concentration of the reactant in solution.
a. first order
b. second order
c. zero order
3. The reaction rate is constant regardless of the amount of reactant in solution.
a. first order
b. second order
c. zero order
Answer:
1) first order
2) second order
3) zero order
Explanation:
The curve of a first order reaction shows it to be exponential. In fact for a first order reaction, the concentration at a time t is an exponential function;
[A]t= [Ao] e^-kt
Where
[A]t = concentration at time =t
[Ao]= initial concentration
k= rate constant
t= time
For a second order reaction, the rate of reaction is directly proportional to the concentration of reactants.
For zero order reactions, rate of reaction is independent of concentration hence rate = k(rate constant)
The concentration data has been required for the determination of the rate of reaction. Based on the concentration of reactant and product, the rate has been determined.
1. For the first-order reaction, there has been an exponential increase in the rate of the reaction with the increase in the reactant concentration. The rate has been dependent on the concentration of the reactant.
Thus the correct option is A.
2. Irrespective of the first-order kinetic, in the second-order reaction, the rate of reaction has been directly proportional to the concentration of the reactant in the solution.
Thus option B is correct.
3. The zero-order reaction has been independent of the concentration of the reactant. The rate of reaction has been constant with an increase in the reactant concentration.
Thus option C is correct.
For more information about the rate of reaction, refer to the link:
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what isotope of an atom if it has 29 protons and 36 neutrons
Answer:
POTASSIUM
Explanation:
2 8 8 1________ 1A
A 7.27-gram sample of a compound is dissolved in 250. grams of benzene. The freezing point of this solution is 1.02°C below that of pure benzene. What is the molar mass of this compound? (Note: Kf for benzene = 5.12°C/m.) Ignore significant figures for this problem. Group of answer choices 36.5 g/mol 146 g/mol 292 g/mol 5.79 g/mol 73.0 g/mol
Answer:
The correct answer is 146 g/mol
Explanation:
Freezing point depression is a colligative property related to the number of particles of solute dissolved in a solvent. It is given by:
ΔTf = Kf x m
Where ΔTf is the freezing point depression (in ºC), Kf is a constant for the solvent and m is the molality of solution. From the problem, we know the following data:
ΔTf = 1.02ºC
Kf = 5.12ºC/m
From this, we can calculate the molality:
m = ΔTf/Kf = 1.02ºC/(5.12ºC/m)= 0.199 m
The molality of a solution is defined as the moles of solute per kg of solvent. Thus, we can multiply the molality by the mass of solvent in kg (250 g= 0.25 kg) to obtain the moles of solute:
0.199 mol/kg benzene x 0.25 kg = 0.0498 moles solute
There are 0.0498 moles of solute dissolved in the solution. To calculate the molar mass of the solute, we divide the mass (7.27 g) into the moles:
molar mass = mass/mol = 7.27 g/(0.0498 mol) = 145.9 g/mol ≅ 146 g/mol
Therefore, the molar mass of the compound is 146 g/mol
As temperature decreases, what happens to particles in a material?
Particles become further apart / expand?
Particles become slippery / liquid?
Particles become closer together / contract?
Particles become sticky / plasma?
Answer:
Particles become closer together / contract?
Explanation:
as particles cool down in temp, the particles slow down and compress
Write the net ionic equation for the reaction of aqueous solutions of ammonium chloride and iron(III) hydroxide.
Answer:
[tex]Fe(OH)_3(s)\rightarrow Fe^{3+}(aq)+3OH^-(aq)[/tex]
Explanation:
Hello.
In this case, for the reaction between aqueous solutions of ammonium chloride and iron (III) hydroxide, we have the following complete molecular reaction:
[tex]3NH_4Cl(aq)+Fe(OH)_3(s)\rightarrow 3NH_4OH+FeCl_3[/tex]
And the full ionic equation, taking into account that the iron (III) hydroxide cannot be dissolved as it is insoluble in water:
[tex]3NH_4^+(aq)+3Cl^-(aq)+Fe(OH)_3(s)\rightarrow 3NH_4^+(aq)+3OH^-(aq)+Fe^{3+}(aq)+3Cl^-(aq)[/tex]
Finally, the net ionic equation, considering that spectator ions are NH₄⁺, Cl⁻ as they are both the left and right side, therefore, the net ionic equation is:
[tex]Fe(OH)_3(s)\rightarrow Fe^{3+}(aq)+3OH^-(aq)[/tex]
Best regards.
The net ionic equation for the reaction of aqueous solutions should be Fe(Oh)3 ➡Fe3+(aq) + 3OH^-(aq).
Net ionic equation:
When the reaction lies between the between aqueous solutions of ammonium chloride and iron (III) hydroxide
So, here the total reaction should be
3NH4Cl(aq) + Fe(OH)3(s) ➡ 3NH4OH + FeCl3
So, here net ionic equation, considering that spectator ions are NH₄⁺, Cl⁻ since they are both the left and right sides.
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Help
please i’m giving out brainly PLEASEE HELPP
Answer:
Abrasion
Explanation:
What is the dependent variable? Be specific. *
If a teacher washes the tops of the student
desks with rubbing alcohol daily, the
spread of germs in the classroom may be
diminished.Be specific when you write your answer HELPPPPP I NEED IT ASAP!
A 50.0 g sample of an unknown substance, initially at 20.2 °C, was heated with 1.55 kJ of energy. The final temperature of the substance was 125.0 °C. Determine the specific heat of this substance.
Answer:
0.296j/g⁰c
Explanation:
we have the following information from this question before us.
mass iv substance = 50grams
we have initial temperature ti = 20.2⁰c
final temperature = 125⁰c
the energy that was provided = 155kj
we proceed with this formula
energy = mcΔT
1.55x10³ = 50 x c x (125-20.2)
1.55x10³ = c x 50gm x 104.8k
we divide through to get c
c = 1.55x10³/50g x 104.8
c = 0.296J/g⁰c
that is the specific heat of this substance.
thank you!
Which of the following favors the solubility of an ionic solid in a liquid solvent? Group of answer choices a large magnitude of the solvation energy of the ions a small magnitude of the lattice energy of the solute a large polarity of the solvent all of the above none of the above
Answer:
all of the above
Explanation:
The solubility of an ionic solid in a liquid solvent largely depends on three factors:
i) The solvation energy
ii) The lattice energy of the solid
iii) The polarity of the of the solvent
A large solvation energy and a small magnitude of lattice energy means that the ionic solute will dissolve very easily in the solvent.
Secondly, the solvent must have a large polarity, this is why water serves as a good solvent for most ionic solutes.
A block of aluminum weighing 100g is cooled from 108.4°C to 68.2°C
with the release of 1080 joules of heat. From this data, calculate the
specific heat of aluminum
Answer:
Specific heat of aluminum = 0.27 j/g.°C
Explanation:
Given data:
Mass of Al = 100 g
Initial temperature = 108.4°C
Final temperature = 68.2°C
Heat released = -1080 j
Specific heat of aluminum = ?
Solution:
Formula:
Q = m.c. ΔT
Q = amount of heat absorbed or released
m = mass of given substance
c = specific heat capacity of substance
ΔT = change in temperature
ΔT = 68.2°C - 108.4°C
ΔT = - 40.2°C
Q = m.c. ΔT
-1080 j = 100 g ×c ×- 40.2°C
-1080 j = -4020 g.°C ×c
c = -1080 j/-4020 g.°C
c = 0.27 j/g.°C
Cations are always
Question Blank
than the neutral atom.
molecular formula of C4H5
Answer:
Cyclopropylmethylene
what are the benefits of using supercritical fluids in EGS
Answer:
See detailed explanation.
Explanation:
Hello.
In this case, it is firstly necessary to cite that EGS accounts enhanced geothermal systems which are man-made reservoirs, placed where lots of hot rock is present but there is lack natural permeability, which requires a fluid to be injected into the subsurface to re-open it and therefore creating permeability.
Typically, water has been used for this purpose, but due to the current issue on saving water alternative methods such as supercritical fluids has been being implemented because they have better dynamic properties such as lower viscosities and therefore larger flow velocities, supercritical CO2 is easy and cheap to get as low temperatures are required to turn it in supercritical condition.
Best regards.!
What element in the second period has the largest atomic radius?
a
neon
b
lithium
c
carbon
d
potassium
Answer:
b) Lithium
Explanation:
Is air a homogeneous heterogeneous mixture or substance
Answer:
look at the explanation
Explanation:
The air that you breathe is a homogeneous mixture of oxygen, nitrogen, argon, and carbon dioxide, along with other elements in smaller amounts. Because each layer of the Earth's atmosphere has a different density, each layer of air is its own homogeneous mixture.
Hope this helps. :)
Use the image above to answer the
question.
1. (6B) What two particles are found in the
nucleus of an atom? (choose two options)
Protons
Neutrons
Nucleus
Electron
Electron cloud
Answer:
A-protons, B-nucleus, D-electrons, C-nucleus, E-electric cloud
Explanation:
an atom contains 31 protons,39neutrons and 31 electrons.Identify the mass number of this atom
Answer:
Atomic mass =70
Explanation:
Mass number is total protons +total neutrons
Draw molecules that satisfy the following prompts:
1. All molecules must have a minimum of 12 Carbon atoms and exactly 3 heteroatoms (not carbon or hydrogen atoms).
2. You may not use the same molecule twice for any parts of this question.
4. You do not need to look up solubility information, but the answers must be reasonable (supported by the concepts that we have discussed). Also, the structures must be reasonable (improper structures, e.g. carbon with 5 bonds or oxygen with one bond and no charge, will not receive any credit).
a. Draw two non-charged molecules that will be separated once they are placed in a separatory funnel that contains 2.5 M HCl(aq) and dichloromethane.
b. Draw two non-charged molecules that will be separated once they are placed in a separatory funnel that contains 2.5 M NaOH(aq) and dichloromethane.
c. Draw two non-charged molecules that will be separated using neutral water and dichloromethane and in a separatory funnel.
Answer:
see images attached
Explanation:
Here we are trying to perform solvent extraction. In solvent extraction, there must be an aqueous phase and an organic phase.
One of the species to be separated is extracted in greater concentration in the aqueous phase while the other is extracted in greater concentration in the organic phase.
The phase into which each specie is extracted depends on the nature of the specie.
Two structures are shown in the images attached that will be separated by the methods shown in (a) (b) (c) in the question
Using charge to describe an atom
Answer:
this atom has nine electrons
Sketch the titration curve for the titration of a generic weak base B with a strong acid. The titration reaction is
B+H+⇌BH+
On the curve indicate the points that correspond to the following:
a) the equivalence point.
b) the region with maximum buffering) the point where pH = pKbd) the region where pH depends only on [B]e) the region where pH depends only on [BH+]f) the region where pH depends only on the amount of excess strong acid
Answer:
Kindly check the attached picture.
Explanation:
Titration is one of the useful concept or practical in chemistry which is used in the determination of the concentration of a particular chemical specie. Without mincing words, let us dive straight into the solution to the question;
(a) Determining the equivalence point using the graph.
=> The equivalence point is the point at which there has been been "enough" addition of the acid to the base to give us the congugate acid. In the diagram showing the curve, it is the point labelled (a).
(b)The next thing is to determine the region with maximum buffering.
=> The position with the maximum buffering ranges from the point labelled (b) in the graph and it is the point when the acid and the base has been added. But the point with the maximum buffering is labeled as point (c).
(c). Determination of the point where pH = pKb.
=> The Point in which the pH = pKb is the point a
(d). The region where pH depends only on [B].
=> The starting point in the point in which the pH is dependent on the concentration of the base, [B].
(e). The region where pH depends only on [BH+].
=> This is the same point with point labelled as (a). Thus, point (a) and (e) are the same.
(f). The region where pH depends only on the amount of excess strong acid is the point labelled as (f) which is known as the post equivalence point.
List the following bonds in order of increasing ionic character: potassium to iodine, carbon to oxygen, lithium to fluorine, boron to fluorine. (Enter the two elements of the bond into the appropriate box: KI, CO, LiF, BF)
Answer:
CO < BF < KI < LiF
Explanation:
The magnitude of ionic character in a bond is dependent on the magnitude of electronegativity difference between the atoms in the bond.
Remember that no bond is 100% ionic or covalent according to Linus Pauling. However, the percentage ionic character depends on electronegativity difference between the bonding atoms and polarizability (Fajan's rules).
Between LiF and KI, Fajan's rules become very important. The Li^+ is small and highly polarizing. The stronger the polarising power of the cation and the higher the polarisability of the anion the more covalent character is expected in a bond
What is the volume of a substance that has a mass of 59 g and a density of 1.98 g/mL?
(show all work)
Answer:
29.8
Explanation:
The formula for volume is mass/ density, so 59/1.98. 29.8 is the answer.
The atoms of which element will gain electrons to form an ion?
oxygen
calcium
lithium
mercury
Explanation:
Oxygen will gain electrons to form ion (O²⁻).
Calcium loses electron to form ion (Ca²⁺)
Lithium loses electron to form ion (Li⁺)
Mercury loses electron to form ion (Hg²⁺)
Here it is stated in question that the element will gain electron it means electron bears negative charge.
Therefore,
Option A is correct ✔.
Please answer !! For chemistry
Answer:
a. is the correct answer
Explanation: