Answer:
The surface temperature of a star determines the color of light it emits. Blue stars are hotter
hope this helps :)
Solutions
Which statement is true of pure substance
1. They may contain one type of atom or one type of molecules.
2.they can only contain one type of molecules.
3.they can contain different types of atoms and molecules.
4.they can only contain one type of atom
This is science btw
Answer:
4
Explanation:
cuz pure substance contain one type of atom,molecule,or cpd.
2 is true but it have wrong grammar,if it contain only one type it must be^^molecule^^
Find the number of CO2 molecules present in 20l of CO2 at 0°C and 772mm of Hg.
I wiLL mark you as brainliest and give 50 points.
Answer:
18
At STP, 22.4 liters of a gas forms one mole that is 6.023×10
23
molecules.
Volume of CO
2
in 1 litre of air =
100
0.03
×1 L
∴ No. of molecules of CO
2
=
22.4
6.023×10
23
×
100
0.03
=8.066×10
18
Explanation:
I guess it's this
[tex]\\ \sf\longmapsto PV=nRT[/tex]
[tex]\\ \sf\longmapsto n=\dfrac{PV}{RT}[/tex]
[tex]\\ \sf\longmapsto n=\dfrac{772(20)}{8.314(273)}[/tex]
[tex]\\ \sf\longmapsto n=\dfrac{15440}{2269.722}[/tex]
[tex]\\ \sf\longmapsto n=6.8mol[/tex]
the Periodic Table •
Class
Key Terms
Key Terms Ch. 4
Use the clues to help you unscramble the Key Terms from the chapter. Then put the
numbered letters in order to find the answer to the riddle.
Clues
Key Terms
1. A fast-moving electron
given off by a nucleus
during radioactive decay. tbaerlpiaect
2. A term used to describe a
material that can be pounded
into shape
llbeealam
3. The process of oxygen
reacting with a metal to
form rust
4. A particle in the atomic
nucleus that carries no
charge
5. A horizontal row across the
2
rsoooiner
3
ouetnrn
periodic table
roiedp
6. Substance that can only
6
conduct electric current
under certain circumstances. otmidsceuncro
7
7. A term used to describe a
material that can be drawn
into a long wire
lecuitd
8 9
8. Radioactive isotope that can be
followed through a chemical
reaction or an industrial
process
aerrtc
9. The elements in Group 18
of the periodic table
nreti ssgea
11 12
10. The very small center core
of an atom
13
10
cuunsle
Riddle: What chart shows the repeating properties of elements?
Answer:
1 2 3 4 5 6 7 8 9 10 11 12 13
Answer:
your question too long did not read all
Explanation:
Q. What phase change occurs at letter A?
Answer:
Where is the picture? Can't answer without it.
PLEASE HELP IM DESPERATE.
Assume you are performing the calibration step of Experiment 8 and you begin with 80 g of water at 20 oC and 80 g of water at 80 oC. After adding the two portions of water into your calorimeter setup and following the procedure outlined in the experiment, you determine the temperature of the mixed portions of water to be 45 oC. What is the heat capacity of the calorimeter?
Assume room temperature is 25 oC.
Answer:
Reaction time tests can be used to assess an individual's hand-eye coordination. One test involves catching a 1 metre ruler and measuring the distance, d in metres, that the ruler travelled before being caught. The reaction time t seconds is then calculated using the formula: = √2d/9.8
How many cl- ions are there in 2. 50 kg of barium chooride.
Solid calcium hydroxide is dissolved in water until the pH of the solution is 11.44. The hydroxide ion concentration [OH–] of the solution is:______.A. 1.1 * 10-11 M.B. 3.06 M.C. 8.7 * 10-4 M.D. 1.0 * 10-14 M.E. None of these.
Answer:
c the answer is c that is the answer
An unknown element sample has 2 isotopes present. The first isotope has a mass of 6.017 amu and is
7.30% abundant. The second has a mass of 7.018 amu and an abundance of 92.7%. Calculate the
average atomic mass of this element
Answer:
Calculating Atomic Mass
Change each percent abundance into decimal form by dividing by 100. Multiply this value by the atomic mass of that isotope. Add together for each isotope to get the average atomic mass.
Explanation:
have a nice day
If i initially have a gas with a pressure of 84 kpa and a temperature of 350 c and i heat it an additional 230 degrees, what will the new pressure be? assume the volume of the container is constant.
Answer:
67.824
Explanation: You want to use the combined gas law equation (P1*V1)/(n1*T1)=(P2*V2)/(n2*T2). So first cross out what remains constant, so volume(V) and I assume moles (since it was not mentioned as a change). Then you can solve algebraically for the answer!
Hope this helped!
The new pressure will be 139.2 kpa .
What is the combined Gas Law?According to combined gas law,
[tex]\rm\dfrac{PV}{nT} = R[/tex]
In the Combined Gas Law,if we change either one of the variables the others will also change.
When the moles of the gas is constant , the above equation can be written as ,
[tex]\rm \dfrac{P'V'}{T'}= \dfrac{PV}{T}[/tex]
Given is P = 84kpa , T= 350⁰ C and T' = 350+230=580⁰ C , V=V' , P'=?
So we will substitute the values in the above formula keeping volume constant.
[tex]\rm \dfrac{P'}{T'}= \dfrac{P}{T}[/tex]
[tex]\rm\dfrac{P'}{580}= \dfrac{84}{350}[/tex]
[tex]\rm P' = \dfrac{84\times 580}{350}[/tex]
[tex]\rm P'= 139.2 \;kpa[/tex]
Therefore the new pressure will be 139.2 kpa .
To know more about Combined Gas Law:
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#SPJ2
Give 2 reason why cryolite is used
In a few minutes, you will work with your partner to create three dances—one for each of the three phases. Each dance will represent the molecular freedom of movement of that particular phase.
If needed, navigate back to My Work to refer to your homework from Lesson 1.4. Then, begin brainstorming ideas for movements that would show these phases.
Dance ideas for solids:
Dance ideas for liquids:
Dance ideas for gases:
What do each of the' rings represent in the Bohr models?
Answer:
The energy levels or electron shells of an atom.
Answer:
Each ring represents a different energy level for the electrons. Each ring has a maximum number of electrons that it can hold. The first (inner) ring can only hold two electrons, the second level can hold eight, the third can hold 18 and the fourth holds 32.
Hope this helps :)
T or F: Lone pairs around the oxygen atom of a water molecule play no role in determining its molecular geometry?
Answer:
Explanation:
They play a very important part. The geometry is not a straight line. It is an angle over 90 which means that the molecule has the same general shape as a boomerang. The two hydrogens and the 2 lone electron pairs try to get away as far as possible from each other. The actual shape results in a tetrahedron shape. But the two hydrogens and 1 oxygen actually look like the aforementioned boomerang.
Water (H2O) is a liquid at room temperature, while carbon dioxide (CO2) is a gas at room temperature. Why? Choose the two statements that apply.
Water has relatively strong hydrogen bonds holding the molecules together but CO2 has only dispersion forces acting as intermolecular forces. The weaker intermolecular forces explains why CO2 is a gas whereas H2O is a liquid at room temperature
How does acid base extraction work.
Answer:
it can be done using the method of lithium paper
Add 2 teaspoons of baking soda and 2 teaspoons of citric acid to the foam cup. Add the half cup of water to the cup and stir. What is the temperature?
Answer:
Test for carbon dioxide gas.
The reaction between baking soda and citric acid will form sodium ions, citric acid ions, carbon dioxide gas, and water. So all you have to do is add the gas produced (by gas displacement method or something) and test whether the gas is carbon dioxide, with lime water or other methods like hydrogencarbonate indicator. Hope this helped!
Explanation:
Answer:
depends on amount, but the reaction's endothermic (meaning its cold, absorbs heat from surroundings)
I hope it helps.
What is the correct formula for tetraphosphorous octaoxide
P4O10
P4O8
Ph4O8
P5O8
P_4O_8
How?
Let's learn how to create name of compound from its name.
Look below for root words
2-di 3-tri4-tetra5-pent6-hex7-hept8-oct9-non10-decHence formula of the compound is P4O8
What is the unabbreviated electron configuration for Barium?
Answer:
[Xe] 6s2
Explanation:
hope it helps Electron configuration
14. Write a statement that makes a claim about arrangements of electrons and properties
within a family of elements.
i dont know
Explanation:
Which of the following is NOT a conductor of heat?
A. a plastic pot handle
B. a copper pan
C. a metal spoon
A) A plastic pot handle.
Explanation:Metals are very good conductors of heat because they contain delocalised electrons that can flow through the metal, transferring heat.
Both a copper pan and a metal spoon are made of metals, so are very good conductors of heat.
Plastic is an insulator, the opposite of a conductor. This makes it very bad at conducting heat, which is why it is used as the handle (it stops you burning yourself when you hold the pot). The answer is therefore A.
what element is 1s2 2s2 2p3
Convert 1.56x10^30 particles of sodium chloride to grams of sodium chloride
Answer:
I cannot tell yet
Explanation:
I don't take that class yet but ill get back to you
What is the molar mass of an unknown gas with a density of 3.35 g/L at 1.00 atm and 25.0 °C
Answer:
[tex]\implies \sf D = \dfrac{PM}{RT}[/tex]
[tex]\implies \sf 3.35= \dfrac{1 \times M}{ \frac{1}{12} \times 298}[/tex]
[tex]\implies \sf 3.35= \dfrac{12\times M}{ 298}[/tex]
[tex]\implies \sf 3.35 \times 298= 12\times M[/tex]
[tex]\implies \sf 998.3= 12\times M[/tex]
[tex]\implies \sf M = \dfrac{998.3}{12} [/tex]
[tex]\implies \bf M = 83.1917 \: \frac{g}{mol} [/tex]
a. What are the half-reactions for the redox reaction CuCl2 + Zn → ZnCl2 + Cu? Label the oxidation
reaction and the reduction reaction. (1 point)
PLS HELP 100 points
The oxidation half equation is Zn ------> Zn^2+ + 2e while the reduction half equation is Cu^2+ + 2e------> Cu.
A redox reaction is a reaction in which there is a loss/gain of electrons. The specie that gives out electrons experiences an increase in oxidation number while the specie that gains the electrons experiences a decrease in oxidation number.
For the reaction; CuCl2 + Zn → ZnCl2 + Cu
The oxidation half equation is;
Zn ------> Zn^2+ + 2e
The reduction half equation is;
Cu^2+ + 2e------> Cu
The chloride ion is excluded because its oxidation number does not change from left to right in the reaction.
Learn more: https://brainly.com/question/967776
what is air pressure? In your own words
Answer:
The amount of force applied on an object that is moving in motion
Explanation:
22) Calculate the energy of a photon of radiation with a frequency of 9.50 x 1013 Hz.
The energy of the photon with a frequency of 9.50×10¹³ Hz is 6.29×10¯²⁰ J
From the question given above, the following data were obtained:
Frequency (f) = 9.50×10¹³ Hz
Planck's constant (h) = 6.626×10¯³⁴ Js
Energy (E) =?The energy of the photon can be obtained as follow:
E = hf
E = 6.626×10¯³⁴ × 9.50×10¹³
E = 6.29×10¯²⁰ JTherefore, the energy of the photon is 6.29×10¯²⁰ J
Learn more: https://brainly.com/question/7957705
Why do metals form cations and nonmetals form anions?
[tex]▪▪▪▪▪▪▪▪▪▪▪▪▪ {\huge\mathfrak{Answer}}▪▪▪▪▪▪▪▪▪▪▪▪▪▪[/tex]
Metals have tendency to loose electrons in order to get noble gas configuration, therefore they loose electrons to form Cations (positively charged ions)
for example ~ Sodium forms Na+
And
Non - metals have tendency to gain electrons in order to attain noble gas configuration , hence they gain electron from somewhere and bears a negative charge forming Anion.
for example ~ Chlorine forms Cl-
Question ( please help me )
1 . Which diagram shows pure substance that are elements
2. Which diagram shows pure substance are compounds
3. Which diagram shows a mixture of compounds
4. Which diagram shows a mixture of elements
5. Which diagram shows a mixture of an element and a compound
Answer:
1. F, H, E
2. A, D, I
3. G
4. E, B, H
5. C
Explanation:
If you have a 100g of Boron and you want to find out how
many molecules of Boron you have, you would need to...
Answer:
5.57 x 10^24 atoms
Explanation:
first, you are seeking the number of ATOMS of Boron.
Boron has an Atomic mass of 10.8 g/mol (see #5 on the periodic table)
100 gm of Boron would have 100 g /10.8 g/mol =9.26 moles
each mole has Avogadros number of atoms 6.02 x 10^23
9.26 moles has 9.26 x 6.02 x 10^23 atoms =5.57 x 10^24 atoms
How does a phase change from solid to liquid occur in a substance?(1 point)
Answer:
As heat is added to solid water, the temperature increases until it reaches 0 °C, the melting point. At this point, the phase change, added heat goes into changing the state from a solid to liquid. Only when this phase change is complete, the temperature can increase.
hope this helps
Heat is responsible for the change of phase from solid to liquid state.
A phase change from solid to liquid occur in a substance by heating of that substance because the bonds present between solid particles can be broken down with the help of heat energy.
When the bond is heat at the temperature on which it is broken down, the solid particles are converted into liquid substance so we can conclude that heat is responsible for the change of phase from solid to liquid state.
Learn more: https://brainly.com/question/25664350
