Scientists find out about atoms before technology from X-ray
There are three ways that scientists have proved that these sub-atomic particles exist and they are direct observation, indirect observation or inferred presence and predictions from theory or conjecture and scientists in the 1800's were able to infer a lot about the sub-atomic world from chemistry.
If X-rays let chemists peer at the structure of atoms, scanning tunneling microscopes finally revealed the atoms themselves scientists believed that atoms were uniform, solid, hard, incompressible, and indestructible and that they moved in infinite numbers through empty space until stopped and differences in atomic shape and size determined the various properties of matter.
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write the molecular and net ionic equation for the following aqueous reactions. If no reaction occurs write NR
Answer:
a. Molecular equation: AgNO₃(aq) + NaI(aq) ----> NaNO₃(aq) + AgI(s)
Net ionic equation: Ag⁺(aq) + I⁻ ---> AgI(s)
b. Molecular equation: Ba(NO₃)₂(aq) + K₂SO₄(aq) ----> 2KNO₃(aq) + BaSO₄(s)
Net ionic equation: Ba²⁺(aq) + SO₄²⁻(aq) ---> BaSO₄(s)
c. Mg(NO₃)₂ + K₂SO₄ ------> No reaction
d. CaCl₂ + AI(NO₃)₃ ----> No reaction
Note: The question is incomplete. A complete similar question is given below:
Write the molecular equation and the net ionic equation for each of the following aqueous reactions. If a reaction is not carried out, write NR after the arrow.
a. AgNO₃ + NaI⁻
b. Ba(NO₃)₂ + K₂SO₄
c. Mg(NO₃)₂ + K₂SO₄
d. CaCl₂ + AI(NO₃)₃
Explanation:
a. A double displacement reaction occur between aqueous solutions of silver nitrate and sodium iodide to give a precipitate of silver iodide.
Molecular equation: AgNO₃(aq) + NaI(aq) ----> NaNO₃(aq) + AgI(s)
Net ionic equation: Ag⁺(aq) + I⁻ ---> AgI(s)
b. A double displacement reaction occurs between aqueous solutions of barium nitrate and potassium sulfate to produce a precipitate of barium sulfate
Molecular equation: Ba(NO₃)₂(aq) + K₂SO₄(aq) -----> 2KNO₃(aq) + BaSO₄(s)
Net ionic equation: Ba²⁺(aq) + SO₄²⁻(aq) ---> BaSO₄(s)
c. Since no precipitate is formed when aqueous solutions of magnesium nitrate and potassium sulfate are mixed together, no reaction occurs
Mg(NO₃)₂ + K₂SO₄ ------> No reaction
d. Since no precipitate is formed when aqueous solutions of calcium chloride and aluminum nitrate are mixed together, no reaction occurs
CaCl₂ + AI(NO₃)₃ ----> No reaction
What is the density of a glass piece that has mass of 18 g and a volume of 24 mL?
Answer:
The answer is 0.75 g/mLExplanation:
The density of a substance can be found by using the formula
[tex]density = \frac{mass}{volume} \\ [/tex]
From the question we have
[tex]density = \frac{18}{24} = \frac{3}{4} \\ [/tex]
We have the final answer as
0.75 g/mLHope this helps you
is the movement of particles from an area of higher concentration to an area of lower concentration
Answer:
The answer is Diffusion.
Answer:
Hypertonic
Explanation:
1. With the aid of a Hess cycle, determine the enthalpy of the decomposition reaction of sodium nitrate, NaNO3 to sodium nitrite, NaNO2 and oxygen, O2. [5]
Enthalpy of formation of NaNO3 = -468 kJ/mol
Enthalpy of formation of NaNO2 = -369kJ/mol
Answer:
Explanation:
2NaNO₃ = 2NaNO₂ + O₂
NaNO₃ = NaNO₂ + 1/2 O₂
- 468 kJ -369 kJ 0 kJ
enthalpy of decomposition reaction
= - 369 - ( - 468 ) kJ
= 99 kJ / mol .
Calculate the number of moles of solute in 431.9 L of 0.722 M sodium cyanide.
Answer:
[tex]312 \ mol \ solute[/tex]
General Formulas and Concepts:
Chemistry
Molarity = moles of solute / liters of solutionExplanation:
Step 1: Define variables
M = 0.722
L = 431.9
m = x
Step 2: Solve for x
Substitute: [tex]0.722 \ M=\frac{x \ mol}{431.9 \ L}[/tex]Isolate x: [tex]311.832=x \ mol[/tex]Rewrite: [tex]x=311.832 \ mol[/tex]Step 3: Check
Our smallest sig figs is 3. Follow sig figs rules.
[tex]311.832 \ mol \approx 312 \ mol \ solute[/tex]
A geologist is making observations from atop a small mountain. She sees two parallel faults: one directly to the east and one directly to the west. She concludes that these faults are caused by tension stretching the crust.
From what type of land feature is the geologist making her observations?
plateau
anticline
syncline
fault-block mountain
This is really a science question but i could not find it
Answer:
Fault-Block Mountain
Explanation:
just did test and got it correct UwU
The geologist is making observation from the fault block mountain so that she sees two parallel faults one from east and another from west.
What is fault block mountain?Mountains with fault blocks are identifiable by their great sheer rock faces. These are created when a large rock mass separates from another due to intense subterranean pressure. The fault is the location on the line where this break occurs.
The rocks rise on one side of this breach and sink on the other. Fault blocks are very large blocks of rock, sometimes hundreds of kilometers in extent, created by tectonic and localized stresses in earth's crust. Large areas of bedrock are broken up into blocks by faults. Blocks are characterized by relatively uniform lithology.
The largest of these fault blocks are called crustal blocks. Large crustal blocks broken off from tectonic plates are called terranes. Those terranes which are the full thickness of the lithosphere are called microplates.
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28. A gas exerts pressure at 5atm at 300K. What is the pressure of the gas at 600K?
a) 1 atm b) 10 atm c).1 atm d) 100 atm
Two moles of acetyl chloride was mixed with two moles of dimethylamine. After the reaction is complete, what species can be found in the mixture
Answer:
See explanation
Explanation:
The reaction is shown in the image attached. This reaction occurs by a carbocation (ionic) mechanism.
The lone pair on the nitrogen atom attacks the carbocation leading to the formation of the product as shown in the image attached.
Since the reaction occurs in a 1:1 ratio, two moles of reactants yields two moles of product.
Use the van der Waals equation to calculate the pressure exerted by 1.475 molmol of Cl2Cl2 in a volume of 4.635 LL at a temperature of 299.0 KK .
Answer:
7.812atm
Explanation:
Using Van der Waals equation, which goes as follows:
Pv = nRT
Where;
P is the pressure
V is the volume (4.635L)
n is the number of moles (1.475mol)
T is the temperature (299K)
R is the universal gas constant (0.082057 L atm mol-1K-1)
Pv = nRT
P = nRT/V
P = 1.475 × 0.0821 × 299/4.635
P = 36.2081/4.635
P = 7.812atm
What is the name of the process that is used to clean up environmental waste and how does it work?
Answer:
Environmental cleanup includes removal of heavy metals and other toxic contaminants from the environment and the process is called remediation.
How does Kinetic energy and how does it relates to diffusion and temperature.
HURRY HELPPP!!!!!!!!!!!!!!!!!!!!
Answer:
ok
Explanation:
khfdnkv Klein pick pick or en la Web outta
What volume of 0.150 M 2 M Li2S solution is required to completely react with 120 mLmL of 0.150 M Co(NO3)2 MCo(NO3)2
Answer:
Explanation:
M1V1=M2v2
M1=0.150M
M2=0.150M
V2=120*10^-3
V1=M2V2/M1
V1=0.150*120*10^-3/0.150
V1=0.12
0.12 mL volume of 0.150M 2M Li₂S solution is required to completely react with 120 mL of 0.150M Co(NO₃)₂ MCo(NO₃)₂.
What is the relation of volume with molarity?
With M1 and M2 representing the molarity of the solutions, expressed as mol/L or M, and V1 and V2 representing their respective volumes, this calculator may be used to calculate a missing number for the dilution equation.
A solution's concentration is determined by multiplying its volume by its molarity (M1V1 = M2V2) On both sides of the equation, the units should stay the same.
Here
M₁V₁=M₂V₂
M₁=0.150M
M₂=0.150M
V₂=120 × 10⁻³
V₁=M₂V₂/M₁
V₁=0.150 × 120 × 10⁻³/0.150
V₁=0.12.
Therefore, 0.12 mL volume of 0.150M 2M Li₂S solution is required to completely react with 120 mL of 0.150M Co(NO₃)₂ MCo(NO₃)₂.
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Name 2 ways heat can be transferred through convention.
Answer:
Heat can travel from one place to another in three ways: Conduction, Convection and Radiation. Both conduction and convection require matter to transfer heat. If there is a temperature difference between two systems heat will always find a way to transfer from the higher to lower system.
Explanation:
An excess of oxygen reacts with 451.4 g of lead, forming 374.7 g of lead(II) oxide. Calculate the percent yield of the reaction.
Answer: The percent yield of the reaction is 77.0 %
Explanation:
[tex]2Pb+O_2\rightarrow 2PbO[/tex]
[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}[/tex]
[tex]\text{Number of moles of lead}=\frac{451.4g}{207.2g/mol}=2.18moles[/tex]
[tex]\text{Number of moles of lead oxide}=\frac{374.7g}{223.2g/mol}=1.68moles[/tex]
According to stoichiometry:
2 moles of [tex]Pb[/tex] produces = 2 moles of [tex]PbO_2[/tex]
2.18 moles of [tex]Pb[/tex] is produced by=[tex]\frac{2}{2}\times 2.18=2.18moles[/tex] of [tex]PbO_2[/tex]
Mass of [tex]PbO_2[/tex] =[tex]moles\times {\text {Molar mass}}=2.18\times 223.2g/mol=486.6[/tex]
percent yield =[tex]\frac{374.7g}{486.6g}\times 100=77.0\%[/tex]
The process through which professional scientists evaluate the quality of each other’s research is called
group counsel.
group review.
peer counsel.
peer review.
Answer:
peer reveiw
Explanation:
Answer:
Peer review.
Explanation: Ask Edu
Solubility
Mixtures and Solutions
Acellus
If 1.23 g of chlorine gas dissolves in
0.95 L of water at 15.6 psi, at what
pressure (in psi) would you be able
to dissolve 1.89 g in the same
amount of water?
The pressure : 23.48 psi
Further eplanationHenry's Law stated that the solubility of a gas is proportional to its partial pressure
Can be formulated
S = kH. P.
S = gas solubility, mol / L
kH = Henry constant, mol / L.atm
P = partial gas pressure
1.23 g Cl₂MW Cl₂ = 71 g/mol
mol of 1.23 g Cl₂ :
[tex]\tt mol=\dfrac{1.23}{71}=0.017[/tex]
Solubility O₂ : 0.017 mol/0.95 L =0.01789 mol/L
Henry's constant for O₂ :
P = 15.6 psi= 1.061517 atm
[tex]\tt S=kH.P\\\\kH=\dfrac{0.01789}{1,061517}=0.0169[/tex]
1.89 g Cl₂[tex]\tt \dfrac{1.89}{71}=0.026[/tex]
[tex]\tt S=0.026:0.95=0.027\\\\P=\dfrac{S}{kH}=\dfrac{0.027}{0.0169}=1.598~atm=23,48~psi[/tex]
Answer:24.0
Explanation:
Why is it necessary to add concentrated HCl, then water, rather than a solution of HCl to the eudiometer tube
If we add water to a concentrated acid, then the solution may boil very violently, splashing concentrated acid. If add acid to water, the solution that forms is very dilute and a small amount of heat is released.
Why do we add acid to water?When a strong acid is poured into water, it flows down the flask and mixes much better, so no boiling takes place. The addition of water to acid forms an extremely concentrated solution of acid initially. A large amount of heat is released and the solution may boil very violently, splashing concentrated acid out of the beaker and all this because the reaction is exothermic in nature.
The reason this takes place is due to a large amount of energy liberated in the hydration reaction of concentrated ions. Therefore, we add acid to water dropwise for the dilution with constant stirring and not water to acid directly.
If we add water to acid, then an exothermic reaction occurs and the solution may boil very violently. To form the dilute solution of any strong acid, you should add acid to water and the small amount of heat released is not sufficient to vaporize and spatter it.
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Explain how Bohr's model built on the ideas of Einstein and Planck.
Explanation:
Bohr built on Nicholson's idea by adopting the requirement that the angular momentum can have only certain discrete values related to Planck's constant. However Bohr's atom has many orbits for the electrons.
How many Sr2+ ions are present in 0.314 moles of Sr3(PO4)2?
Answer:
5.67x10²³ ions
Explanation:
By looking at the molecular formula, we can tell that there are three Sr²⁺ ions per Sr₃(PO₄)₂ molecule.
We convert Sr₃(PO₄)₂ moles into Sr₃(PO₄)₂ molecules by using Avogadro's number:
0.314 moles * 6.023x10²³ = 1.89x10²³ moleculesFinally we multiply that number by 3 in order to convert Sr₃(PO₄)₂ molecules to Sr²⁺ ions:
1.89x10²³ * 3 = 5.67x10²³ ions.
Arrange the elements in order of increasing atomic size: Li, N, B
Answer:
N, B, Ni
Explanation:
Answer:
Explanation:
Whenever the same two elements form more than one
compound, the different masses of one element that combine
with the same mass of the other element are in the ratio of
small whole numbers.
TRUE
FALSE
Answer:
The answer is true
Explanation: Because The law of multiple proportions states that when two elements react to form more than one compound, a fixed mass of one element will react with masses of the other element in a ratio of small, whole numbers.
Calculate the time required for a constant current of 0.868 A to deposit 0.387 g of Tl(III) as Tl(s) on a cathode.
Answer:
632.7 secs
Explanation:
Equation of the reaction:
Tl^3+ + 3e ------> Tl
If 1F = 96500 C
Q= It
Where;
I= current
t= time
3× 96500 C deposited 204 g of Tl
0.868 × t deposited 0.387 g of Tl
3 × 96500 × 0.387 = 204 × 0.868 × t
t= 3 × 96500 × 0.387/ 204 × 0.868
t= 632.7 secs
The time required for a constant current of 0.868 A to deposit 0.387 g of Tl(III) as Tl(s) is 2689 s
We'll begin by calculating the quantity of electricity needed to deposit 0.387 g of Ti
Ti³⁺ + 3e —> Ti
Recall:
1 mole of Ti = 48 g
1 electron (e) = 96500 C
Thus,
3 electrons = 3 × 96500 = 289500 C
From the balanced equation above,
48 g of Ti was deposited by 289500 C of electricity.
Therefore,
0.387 g of Ti will be deposited by = (0.387 × 289500) / 48 = 2334.09375 C of electricity
Finally, we shall determine the time required.Quantity of electricity (Q) = 2334.09375 C
Current (I) = 0.868 A
Time (t) =?t = Q / I
t = 2334.09375 / 0.868
t = 2689 sTherefore, the time required for the reaction is 2689 s
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Type in the name of the following compounds. Be sure to use the periodic table if needed.
Answer: Sulfuric Acid
Explanation: correct on edg
Answer:
Sulfuric Acid
Explanation:
correct on edg
PART A: Which of the following identifies the central idea of the text? The text is the power of advertising
A. While many people consider advertisements to be annoying, they provide the public with necessary information and services.
B. Advertisement are capable of manipulating people more than they realize, as ads convince consumers that certain products lead to specific emotions and experiences.
C. With the development of technology, advertisements have become more informative and able to cater to specific viewers.
D. Advertisements tend to focus their message on youth, as they are most likely to spend money on trendy products.
Answer: B
Explanation:
Answer: B- Advertising are capable of manipulating...
Explanation:
Please help
It’s super quick
Answer:
1. a
Explanation:
2. c
Answer:
1 is A number two is C
Why do the elements get smaller as you move from the left side to the
right side of the periodic table?
Salt is water solution is made salt or water
Answer:
Both
Explanation:
because salt water comes from water mixing with salt
A(n) ____ consists of atoms that have a specific number of protons in their nuclei.
ion
isotope
element
prototype
solution
Answer:
Solution i think
Explanation:
The period that an element is in on the periodic table can tell you how many _____ the element’s atom have.
A. Energy level(electron shells)
B. valence electrons
C. protons
D. isotopes
WILL BE MARKED BRAINLIEST
PLUS 15 Points
Answer: It's D
Explanation:
which subatomic particles have no charge (they are neutral)?
Answer:
neutron
Explanation:
Neutron, neutral subatomic particle that is a constituent of every atomic nucleus except ordinary hydrogen. It has no electric charge
Answer:
neutrons
Explanation:
protons are positive and electrons are negative