Chemistry College

What is parallax?
O A The distance to nearby stars
O
B. The apparent change in position of a nearby star when looked at from different plac
O C. The apparent change in position of a nearby star over time
O
D. The unit of measurement that describes the change in position of a star over time

Answers

Answer 1

Answer:

Explanation:

Because it is viewed in a different place

Answer 2

Answer:

Answer is B.the apparent change in position of a nearby star when looked at from different place.

Explanation:

I hope this helps!

Related Questions

please help :) hope you have a good day

Answers

Answer:

the volume of the gas will decrease

compound composed of cations and anions the forces of attraction that bind oppositely charged ions together lowest whole-number ratio of ions in an ionic compound a depiction of the valence electrons as dots around the symbol for an element a mixture of two or more elements, at least one of which is a metal the attraction of the free-floating valence electrons for the positively charged metal ions ions of the halogen atoms the electron(s) in the highest occupied energy level of an atom the number of ions of opposite charge that surround each ion in a crystal Atoms in a compound tend to have the electron configuration of a noble gas. Shows the kinds and numbers of atoms in the smallest representative unit of a substance a. halide ions b. alloy c. octet rule d. formula unit e. electron dot structure f. ionic compound g. ionic bonds h. coordination number i. chemical formula j. valence electrons k. metallic bond

Answers

Answer:

compound composed of cations and anions the forces of attraction that bind oppositely charged ions together - ionic compound

lowest whole-number ratio of ions in an ionic compound - formula unit

a depiction of the valence electrons as dots around the symbol for an element - electron dot structure

a mixture of two or more elements, at least one of which is a metal - alloy

the attraction of the free-floating valence electrons for the positively charged metal - metallic bond

ions of the halogen atoms - halide ions

the electron(s) in the highest occupied energy level of an atom - valence electrons

the number of ions of opposite charge that surround each ion in a crystal - coordination number

Atoms in a compound tend to have the electron configuration of a noble gas - octet rule

Shows the kinds and numbers of atoms in the smallest representative unit - chemical formula

Explanation:

An ionic compound is composed of oppositely charged ions held together in a crystal lattice. The lowest whole-number ratio of ions in an ionic compound is known as the formula unit. The number of ions of opposite charge that surround each ion in a crystal is called the coordination number. Ions of the halogen atoms are negatively charged and are called halide ions

Elements are composed of atoms, the electron(s) in the highest occupied energy level of an atom are called valence electrons. In metals, the attraction of the free-floating valence electrons for the positively charged metal is called the metallic bond. For atoms of elements, a depiction of the valence electrons as dots around the symbol for an element is called the electron dot structure or Lewis structure.

A combination of elements may be a compound or an alloy. An alloy usually contains at least one metal. For compounds, the chemical formula Shows the kinds and numbers of atoms in the smallest representative unit. Atoms form compounds because atoms in a compound tend to have the electron configuration of a noble gas this is the octet rule.

The correct match of the given statement are 1 - f. ionic compound, 2- d. formula unit, 3 - e. electron dot structure, 4- b. alloy, 5- k. metallic bond, 6- a. halide ions, 7- j. valence electrons, 8- h. coordination number, 9 - c. octet rule, 10- i. chemical formula.

Ionic compounds are made up of oppositely charged ions that are kept together in a crystal lattice. The formula unit is the lowest whole-number ratio of ions in an ionic compound.

The coordination number is the number of ions with opposite charges that surround each ion in a crystal. Halide ions are halogen atom ions that are negatively charged.

Elements are made up of atoms, and the electron(s) in the atom's highest occupied energy level are known as valence electrons. The metallic bond refers to the attraction of free-floating valence electrons to positively charged metals in metals.

The electron dot structure or Lewis structure is a representation of the valence electrons as dots around the symbol for an element for atoms.

A compound or an alloy is a mixture of components. A metal is frequently present in an alloy.

The chemical formula is used for compounds. The types and numbers of atoms in the smallest representative unit are displayed.

The octet rule states that atoms in a compound tend to have the electron configuration of a noble gas.

Therefore, the correct matches are: 1 - f. ionic compound, 2- d. formula unit, 3 - e. electron dot structure, 4- b. alloy, 5- k. metallic bond, 6- a. halide ions, 7- j. valence electrons, 8- h. coordination number, 9 - c. octet rule, 10- i. chemical formula.

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The given question is incomplete, so the most probable complete question is,

Match the correct statement with their appropriate terms:

Compound composed of cations and anions, the forces of attraction that bind oppositely charged ions together.Lowest whole-number ratio of ions in an ionic compound.A depiction of the valence electrons as dots around the symbol for an element.A mixture of two or more elements, at least one of which is a metal.The attraction of the free-floating valence electrons for the positively charged metal.Ions of the halogen atoms.The electron(s) in the highest occupied energy level of an atom.The number of ions of opposite charge that surround each ion in a crystal.Atoms in a compound tend to have the electron configuration of a noble gas.Shows the kinds and numbers of atoms in the smallest representative unit.

An unknown organic compound containing carbon, hydrogen, and oxygen, is subjected to combustion analysis. When 3.498 g of the unknown compound is combusted, 7.950 g of CO2 and 3.255 g of H2O is formed. What is the molecular formula of the unknown compound if its molar mass is 174.27 g/mol?

Answers

Answer:

Molecular formula for the organic compound is: C₉H₁₈O₃

Explanation:

We determine the combustion reaction:

CₓHₓOₓ + O₂ → CO₂ + H₂O

We don't know the subscrip of the organic compound, that's why we put x.

Notice we have C in the compound and in CO₂. Let's find out the mass of C. 1 mol of CO₂ contains 1 mol of C

Then (7.950 g /44g/mol) of CO₂ may contain ?

(7.950 g /44g/mol) represents the moles of dioxide → 0.181 moles of C

These moles came from the mass of the organic compound, the 3.498 g.

So now, we can know the subscript for C.

If 3.498 g of the compound contain 0.181 moles of C

174.27 g of the compound may contain (174.27 . 0.181)/ 3.498 = 9

Let's do the same for the H.

1 mol of water contain 2 moles of H

(3.255 g /18 g/mol) of water, may contain ?

3.255 g /18 g/mol = 0.181 moles . 2 = 0.362 moles of H

These moles came from the mass of the organic compound, the 3.498 g.

Let's find out the subscript for H

If 3.498 g of the compound contain 0.362 moles of H

174.27 g of the compound may contain (174.27 . 0.362)/ 3.498 = 18

Organic compound is C₉H₁₈Oₓ. If the molar mass is 174.27 g we can easily determine the moles of O

12 g/mol . 9 + 1 g/mol . 18 + 16 g/mol . X = 174.27 g/mol

(174.27 g/mol - 12 g/mol . 9 - 1 g/mol . 18 ) / 16 = 3

Molecular formula for the organic compound is: C₉H₁₈O₃. Therefore the complete combustion reaction is:

C₉H₁₈O₃ + 12O₂ → 9CO₂ + 9H₂O

5 Describe how seawater forms layers

Answers

Answer:The ocean forms layers because the water has different density throughout. 2. Water with higher density sinks to the bottom while water with lower density sits on the top. ... Low-density water tends to be warmer and less saline, while high-density water is generally cooler and more saline.

Explanation:

I am a teacher in a college in a large city in China. One day, some students asked me to join
them for dinner. They said they wanted to take me to a very special restaurant that had
just opened. This new place served American food. The students were proud that their city
had a restaurant that served fine American food. I was quite surprised when we got to the
restaurant. My students had taken me to a very well-known fast food restaurant!
1.
In the paragraph above, the author's purpose is to
А. inform.
B
entertain
share personal experiences
C
D
persuade

Answers

Answer:

c or b

Explanation:

the story is entertaining and it shares the teachers personal experiences with the teachers students

how to get a girlfrend at age 70

Answers

Be that playa boyyyyy

The following are all examples of good titration reactions with the exception of _____________. (7-2) Group of answer choices Ammonia (NH3) titrated with HCl titrant. Formic acid titrated with ammonia (NH3) as a titrant. I- titrated with Ag titrant, forming a complex with a tiny Ksp. Potassium Hydrogen Phthalate (KHP) titrated with NaOH titrant. NaOH titrated with HBr titrant.

Answers

Answer:

Formic acid titrated with ammonia (NH3) as a titrant

Explanation:

We have to look at something very critical here and that is, considering whether the acid/ base is strong or weak.

For a weak acid weak base titration, there is no suitable indicator neither is there any sharp pH range because no sharp change occurs. So, for a weak acid-weak base titration, there is only a very small change in pH at the equivalence point. This makes it impractical to carry out a weak acid- weak base titration.

Formic acid is a weak acid and ammonia is a weak base. Hence, Formic acid titrated with ammonia (NH3) as a titrant is a bad titration

Hail is falling down from the sky at 50 miles per hour. Is this an example of speed,
velocity or acceleration?

Answers

Explanation:

tgggghhhhijyyhhjjjjjjjj

Which of these statements is false?
A. All matter is made up of atoms.
B. Atoms are made up of protons,
neutrons, and electrons.
C. Atoms contain chemical bonds.
D. Atoms are the smallest particles of
elements.

Answers

Answer:

C is the false one atoms contain chemical bonds

Answer:

C. Atoms contain chemical bonds.

Reason:

Atoms don't have any chemical bonds. Molecules are the particles have chemical bonds.

What are the layers of the Earth

Answers

Hello! Here is your answer!

Crust, Upper Mantle, Lower Mantle, Outer Core

I hope this helped if it did please mark brainlist!

Answer:

They are in order from exterior to the interior - the crust, the mantle, the outer core, and the inner core.

study the image wich shows an air mass moving into a region wich type of weather will this region most likely experience due to the incoming air mass

Answers

Answer:

766ijn

Explanation:

hovibibbunununububububyhybyybybnu

(b) Why must acidic gases be treated before they are released into the atmosphere?

Answers

Answer:

because they react with other gases of atmosphere and pollute the environment

An airplane has a mass of 12,000kg. If it is accelerating at 16m/sec2, what is its force?(round to the nearest whole number) NEED THIS ASAP

Answers

Answer:

[tex]F=1.92x10^5N[/tex]

Explanation:

Hello!

In this case, since the force exerted by an object with a certain mass an acceleration is:

[tex]F=m*a[/tex]

We can plug in the given mass of 12,000 kg and acceleration of 16 m/s^2 to obtain:

[tex]F=12,000kg*16m/s^2\\\\F=192,000kg*m/s^2\\\\F=1.92x10^5N[/tex]

Best regards!

Find the number of moles in 25.0g of ammonium

Answers

Answer:

1.389 moles

Explanation:

We are given that

Given mass of ammonium=25.0 g

We have to find the number of moles in 25.0g of ammonium.

The chemical formula of ammonium [tex]NH^{+}_4[/tex]

Molar mass of N=14, Molar mass of H=1

Molar mass of ammonium (NH4+)=14+4(4)=18 g/mol

We know that

Number of moles=Given mass/Molar mass

Using the formula

Number of moles of ammonium=[tex]\frac{25}{18}[/tex]moles

Number of moles of ammonium=1.389 moles

Hence, the number of moles in 25.0g of ammonium=1.389 moles

Which of the following has the strongest gravitational field?
A. the sun
B. the earth
C. a football player
D. a tree

Answers

Answer:

Explanation:

Answer:

the sun , option A hope it helps

10. Imagine that the unknown solution contains aqueous ammonium sulfate, which is commonly used in fertilizer. For the precipitation of barium sulfate after mixing aqueous ammonium sulfate solution and barium chloride solution (the reactants), write the (1) balanced molecular equation, (2) the complete ionic equation, (3) the net ionic equation AND identify the spectator ions, if any.

Answers

Answer:

(1) (NH₄)₂SO₄(aq) + BaCl₂(aq) ⇒ BaSO₄(s) + 2 NH₄Cl(aq)

(2) 2 NH₄⁺(aq) + SO₄²⁻(aq) + Ba²⁺(aq) + 2 Cl⁻(aq) ⇒ BaSO₄(s) + 2 NH₄⁺(aq) + 2 Cl⁻(aq)

(3) SO₄²⁻(aq) + Ba²⁺(aq) ⇒ BaSO₄(s)

(4) NH₄⁺ and Cl⁻

Explanation:

(1) Let's consider the molecular equation that occurs after mixing aqueous ammonium sulfate solution and barium chloride solution. This is a double displacement reaction.

(NH₄)₂SO₄(aq) + BaCl₂(aq) ⇒ BaSO₄(s) + 2 NH₄Cl(aq)

(2) The complete ionic equation includes all the ions and insoluble species.

2 NH₄⁺(aq) + SO₄²⁻(aq) + Ba²⁺(aq) + 2 Cl⁻(aq) ⇒ BaSO₄(s) + 2 NH₄⁺(aq) + 2 Cl⁻(aq)

(3) The net ionic equation includes only the ions that participate in the reaction (not spectator ions) and the insoluble species.

SO₄²⁻(aq) + Ba²⁺(aq) ⇒ BaSO₄(s)

(4) The spectator ions are NH₄⁺ and Cl⁻.

why is seawater a better conductor of electricity than freshwater?

Answers

Answer:

please refer to the attachment above;)

Answer:

Because it contains Na+ and Cl- ions, Which are conductors of electricity

Explanation:

Explain the effects distance and mass have on the gravitational pull of the planets.

Answers

Answer:

Gravity is normal...

Explanation:

Objects with more mass have more gravity. Gravity also gets weaker with distance. So, the closer objects are to each other, the stronger their gravitational pull is. Earth's gravity comes from all its mass. So, theoretically speaking planets move or get pulled due to their huge amount of mass.

(GIVING BRAINLIEST!!)
Identify and describe the different forms of precipitation shown in the images.

Answers

Answer:

snow, hail, rain

Explanation:

precipitation is the transfer of water in any form from the atmosphere to the land or sea surface

Forms of Precipitation. It can be liquid or solid; the main precipitation types are rain, sleet, snow, ice pellets, hail, and drizzle.

Why are there different forms of precipitation?

There are different forms of precipitation based on atmospheric conditions. Warmer atmospheric conditions might result in rain, drizzle, or hail (if it's a thunderstorm). Colder atmospheric conditions might result in snow, sleet, freezing rain, or ice crystals.

What are the 4 main types of precipitation?

The four main types of precipitation are rain, snow, sleet, and hail. Rain is liquid precipitation that falls during many parts of the year. Hail is associated with thunderstorms and generally falls in warmer temperatures. Snow and sleet are frozen and generally fall in colder temperatures.

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Hello, this is a science task and it is due today I would really appreciate it if you guys can help me answer and explain what is the difference between expansion and contraction:) I will mark brainliest!

Answers

Answer:

Expansion: increase in size Contraction: decrease in size

Explanation:

The increase in size of an object on heating is called expansion where as the decrease in size of an object on cooling is called contraction.

Which of the following particles has the smallest
mass?
A) electron
C) neutron
B) hydrogen atom
D) proton

Answers

Answer:

AN ELECTRON HAS THE SMALLEST MASS!

Answer:

A) electron

good luck, i hope this helps :)

After adding 20.0 mL of 5% NaOH solution into the remaining organic layer, followed by mixing and venting, the solution separated into two distinct layers. Match the following: Group of answer choices The top layer was the ______________ layer. [ Choose ] 9-fluorenone was most soluble in the ____________ layer. [ Choose ] deprotonated chloroanilic acid was most soluble in the _____________ layer. [ Choose ] The bottom layer was the __________________ layer. [ Choose ] The organic layer was a ________________ colored solution. [ Choose ] The aqueous layer turned into a _____________ colored solution. [ Choose ]

Answers

Answer:

The top layer was the organic layer.

9-fluorenone was most soluble in the organic layer.

Deprotonated chloroanilic acid was most soluble in the aqueous layer.

The bottom layer was the aqueous layer.

The organic layer was a yellow colored solution.

The aqueous layer turned into a pink colored solution.

According to this video, how do scientists use data to study/monitor earthquakes and tsunamis?

Answers

Answer:

ewan ko po

Explanation:

sana makatulong

PLEASE HELP ME!! DIMENSIONAL ANALYSIS
CHEMISTRY
DUE IN 5 MINS!!!

Answers

Answer:

12 mi/h

Explanation:

Step 1: Given data

Total distance (d): 6 kmTime elapsed (t): 19 min

Step 2: Convert "d" to miles

We will use the conversion factor 1 mi = 1.60934 km.

6 km × 1 mi/1.60934 km = 3.7 mi

Step 3: Convert "t" to hours

We will use the conversion factor 1 h = 60 min.

19 min × 1 h/60 min = 0.32 h

Step 4: Calculate the average speed of the runner (s)

The speed is equal to the quotient between the total distance and the time elapsed.

s = d/t

s = 3.7 mi/0.32 h = 12 mi/h

What mass of iron is produced from adding 80.0 g of iron(II) oxide (71.85 g/mol) to 20.0 g of magnesium metal? FeO (l) + Mg (l) ----------> Fe (l) + MgO (s) Identify the limiting reactant, mass of iron produced and the mass in grams of the excess reactant used in this reaction. Remember to report the correct number of significant figures and units where appropriate. You need to show work in order to receive credit. Zero points will be awarded if logical work/explanation is not given. You must show your work by typing it into the provided test box. I will not look to your scratch paper for work.

Answers

Answer:

46.0g of Iron are produced

Explanation:

Based on the chemical reaction:

FeO(l) + Mg(l) → Fe(l) + MgO(s)

1 mole of Iron (II) oxide reacts per mole of Mg to produce 1 mole of iron

To solve this question we need to convert each mass of reactant to moles using its respectives molar masses in order to find limitng reactant. Moles of limiting reactant = Moles of iron produced:

Moles FeO (Molar mass: 71.85g/mol):

80.0g * (1mol / 71.85g) = 1.11moles FeO

Moles Mg (Molar mass: 24.305g/mol)

20.0g * (1mol / 24.305g) = 0.823 moles Mg

As moles of Mg < Moles FeO, Mg is limiting reactant and the moles of Fe are 0.823 moles.

The mass of Iron produced is:

0.823 moles Fe * (55.845g/mol) =

46.0g of Iron are produced

What is delta Gº for the following reaction at 25 °C?
CO(g) + 2 H2(g) = CH OH(9)
Ky = 2.1 x 10-4

Answers

Answer:

21 kJ/mol

Explanation:

Step 1: Given and required data

Temperature (T): 25 °C (298 K)Equilibrium constant (Kc): 2.1 × 10⁻⁴Ideal gas constant (R): 8.314 J/K.mol

Step 2: Write the balanced equation at equilibrium

CO(g) + 2 H₂(g) ⇄ CH₃OH(g)

Step 3: Calculate the standard Gibbs free energy of the reaction (ΔG°)

We will use the following expression.

ΔG° = - R × T × ln Kc

ΔG° = - (8.314 J/K.mol) × 298 K × ln 2.1 × 10⁻⁴ = 2.1 × 10⁴ J/mol = 21 kJ/mol

help asap pls,
find the percent composition