Calculate the average atomic mass of unknown element X. You determine that isotope 127X makes up 80%, isotope 126X makes up 17%, and isotope 128X makes up 3%.

A. 127.10 amu
B. 126.86 amu
C. 127.54 amu
D. 126.20 amu

Answer:

1. 1g/ml

Explanation:

1. Density is mass divided by volume (g/mL).

10g/10mL = 1 g/mL

2. When you already know the density and the volume, you can use the density as a unit converter.

[tex]5mL*\frac{20g}{mL} = 100g[/tex]

3. It's the same with density and mass.

[tex]20g*\frac{1mL}{5g} = 4mL[/tex]

The question is incomplete, the complete question is;

All surfaces have texture, which means it affects how things move over it. When it takes a long time for friction to slow down and object, what is MOST LIKELY true about the surface the object is moving on? (A) The surface is dry (B) The surface is rough (C) The surface is uneven (D) The surface is smooth

Answer:

(D) The surface is smooth

Explanation:

Friction exists because of relative motion between two surfaces in contact with each other. However the magnitude of friction depends on how rough or smooth the surface is.

For smooth surfaces, there is little or no resistance to motion as objects move over the surface. Hence objects take a longer time to slow down on a smooth surface due to very little friction.

On a rough surface, objects tend to slow down relatively quickly. Hence, less resistance to motion on a smooth surface makes an object to take a longer time to slow down on a smooth surface than on a rough surface.

Answer: D

Explanation: Because if the surface is smooth it causes it to be more even for it to be able to cause Friction

if you find this helpful, Your welcome, if not, sorry.

Answer:

the volume will expand

Explanation:

gas under pressure contracts, and expands with a lesser pressure

The volume of the hydrogen gas at 25 kPa is 8 Liters.

Explanation:

Given:

At constant temperature, 2 liters of hydrogen gas at 100kPa pressure.

To find:

The volume of the hydrogen gas at 25kPa.

Solution:

The initial pressure of the hydrogen gas =[tex]P_1=100 kPa[/tex]

The initial volume of the hydrogen gas at 100 kPa =[tex]V_1=2 L[/tex]

The final pressure of the hydrogen gas =[tex]P_2=25 kPa[/tex]

The final volume of the hydrogen gas at 25kPa = [tex]V_2=?[/tex]

Using Boyles law:

[tex]P_1V_1=P_2V_2\\100kPa\times 2 L=25 kPa\times V_2\\V_2=\frac{100 kPa\times 2L}{25 kPa}=8L[/tex]

The volume of the hydrogen gas at 25 kPa is 8 Liters.

Learn more about Boyles law here:

brainly.com/question/12835309?referrer=searchResults

brainly.com/question/1437490?referrer=searchResults

Answer:

2

Explanation:

thats the answer.have good day

Answer:

Explanation:

The density of a substance can be found by using the formula

[tex]density = \frac{mass}{volume} \\ [/tex]

So we have

[tex]density = \frac{25}{90} = \frac{5}{18} \\ = 0.277777...[/tex]

We have the final answer as

Hope this helps you

Answer:

Potential Energy is stored energy or energy of position (gravitational). The object isn't moving. For example, a ball being held is potential energy because the object isn't moving but it has the potential of turning into kinetic energy.

Kinetic Energy is the energy of motion. For example, running. You are moving, and there is clear action and activity

Energy stored in an object due to its position is Potiential energy . Energy that is moving object has due to its motion is Kinetic energy .

Answer:

A, True

Explanation:

Answer:

A. Potential energy is stored energy

Explanation:

Answer:

A

Explanation:

i have the same question

Answer:

c. .....................

Answer: the amount of carbon dioxide put into the atmosphere due to your consumption of fossil fuels

Your carbon footprint is the amount of carbon dioxide and other carbon compounds emitted, because of your use of fossil fuels.

Hope this helps!

Answer:

helium

Explanation:

because there are no electrons screening it from the nucleus

Answer:

Orange

Explanation:

I used google my b

Answer:

ORANGE

explanation:

Small pieces of sodium burn in air with often little more than an orange glow. Using larger amounts of sodium or burning it in oxygen gives a strong orange flame.

Answer:the answer is a chemical change, because a gas was produced

Explanation:  yeast is a chemical

Answer:

The answer is C.

"Chemical changes occur when a substance combines with another to form a new substance, called chemical synthesis or, alternatively, chemical decomposition into two or more different substances. These processes are called chemical reactions and, in general, are not reversible except by further chemical reactions."

Explanation:

Alkanes are saturated hydrocarbons that have single bonds in chains

General formula for alkanes :

[tex]\tt \large{\bold{C_nH_{2n+2}}[/tex]

Hydrocarbon combustion reactions (specifically alkanes)

[tex]\large {\box {\bold{C_nH _ (_2_n _ + _ 2_) + \dfrac {3n + 1} {2} O_2 \Rightarrow nCO_2 + (n + 1) H_2O}}}[/tex]

So that the burning of ethane with air (oxygen):

[tex]\tt C_2H_6+\dfrac{7}{2}O_2\rightarrow 2CO_2+3H_2O[/tex]

2C₂H₆ (g) + 7O₂ (g) ⟶ 4CO₂ (g) + 6H₂O (ℓ)

or we can use mathematical equations to solve equilibrium chemical equations by giving the coefficients for each compound involved in the reaction

C₂H₆ (g) + aO₂ (g) ⟶ bCO₂ (g) + cH₂O (ℓ)

C : left 2, right b ⇒ b=2

H: left 6, right 2c⇒ 2c=6⇒ c= 3

O : left 2a, right 2b+c⇒ 2a=2b+c⇒2a=2.2+3⇒2a=7⇒a=7/2

The density of the wood : 1.45 g/cm³

Density is a quantity derived from the mass and volume  

Density is the ratio of mass per unit volume  

With the same mass, the volume of objects that have a high density will be smaller than objects with a smaller type of density  

The unit of density can be expressed in g/cm³ or kg/m³  

Density formula:  

[tex]\large {\boxed {\bold {\rho ~ = ~ \frac {m} {V}}}}[/tex]

ρ = density  

m = mass  

v = volume  

[tex]\tt V=2.7\times 5.5\times 3.9=57.915~cm^3[/tex]

[tex]\tt \rho=\dfrac{m}{V}\\\\\rho=\dfrac{84~g}{57.915~cm^3}=\boxed{\bold{1.45`g/cm^3}}[/tex]

Answer:

10

Explanation:

Khan Academy

Answer:

721.9 grams

I hope this helps!

Answer:

Explanation:

The volume of a substance when given the density and mass can be found by using the formula

[tex]volume = \frac{mass}{density} \\ [/tex]

From the question.

density = 0.017 g/mL

mass = 4 g

We have

[tex]volume = \frac{4}{0.017} \\ = 235.2941176...[/tex]

We have the final answer as

Hope this helps you

Answer:

STANDARD: 0.085 mi, 450 ft, or 150 yds

METRIC: 0.137 km, 137.16 m, or 13716 cm

Explanation:

Answer:

average speed around 9.1 meters/second

Explanation:

400 divided by 43.9

Answer: Summary of Common Properties

Explanation:

May I please have brainiest?

Answer:

The two properties of most non metals are high ionization energy and poor electrical conductivity. The correct option among all the options that are given in the question is option "1". In general it is known that nonmetals are very poor conductors of heat and electricity. The nonmetals that are solid are normally very brittle and has very little or no metallic luster at all. Nonmetals are highly reactive and show variety of chemical properties. It can also be pointed out that the nonmetals gain electrons very easily.

brainliest pleaseee :)

Explanation:

when water is in liquid form and the temperature DROPS it becomes solid ice the process is melting , freezing and evaporation this goes in a circle

since 73% of the isotope is given, take 100%-73% to get the remaining % of the isotopes which is going to be 27%.

hence,

atomic weight= (73×59) + (27×62)

=4307+1302

=5609 amu

Answer:

Explanation:

The density of a substance can be found by using the formula

[tex]density = \frac{mass}{volume} \\ [/tex]

From the question

mass = 21.7 kg = 21700 g

volume = 5.78 cm³

We have

[tex]density = \frac{21700}{5.78} \\ = 3754.3252...[/tex]

We have the final answer as

Hope this helps you