In a sample of 400 lithium atoms, it is found that 30 atoms are lithium-6 (6.015 amu) and
370 atoms are lithium-7 (7.016 amu). What is the average atomic mass?

Answers

Answer 1

Answer:

667.3

Explanation:


Related Questions

Protons have about the same mass as:

A. plasma particles
B. neutrons
C. electrons

Answers

the answer is B. neutrons

1. True or False? The scientific method is defined as a method of research
in which a problem is identified, data is gathered, and a hypothesis is
created based off the data, then the hypothesis is tested.

Answers

Answer:

true

Explanation:

please mark BRAINLIEST

is this correct? say something if it's wrong lol ​

Answers

Answer:

seFG9zuh98gufhIUAFIyhA*UGH8gguuguuuuuuuu

Explanation:

Answer:

Yes that look about right to me :)

Someone drops a book on the floor, and it makes a loud noise. At that time, you turn to look at the person who dropped the book. The loud noise is an example of a…

A. Hydrotropism

B. Stimulus

C. Response

D. Phototropism

Answers

Answer: Stimulus

Explanation: The definition of Stimulus is "a thing or event that evokes a specific functional reaction in an organ or tissue," according to the Oxford Dictionary. So the book dropping and causing a noise is an example of a stimulus.

A sound wave has a frequency of 20 Hz and a wavelength of 100 m. What is speed of the wave

Answers

The speed of a wave can be calculated using this formula:

v = f x λ

Where:

v is the wave speed in metres per second, m/s

f is the frequency in hertz, Hz

λ (lambda) is the wavelength in metres, m

Calculation:

Given:

f = 20 Hz

λ = 100m

Using the equation:

v = f x λ

v = 20 x 100

v = 2000 m/s

Therfore, the speed of the wave is 2000 m/s

A sound wave has a wavelength of 100 m and a frequency of 20 Hz. The wave's speed is 2× 10^3 m/s.

assuming frequency = 20 Hz and wavelength = 100 m

utilized concept: v= = 20×100 = 2×10³ m/s

Why is frequency important?

The frequency in physics is the quantity of waves passing a fixed location in a unit of time. It also indicates how many cycles or vibrations a body in periodic motion experiences in a given unit of time.

How would you define sound?

A sort of energy created by vibrations is sound. The molecules of the air surrounding an item vibrate as a result.. These molecules vibrate because they collide with nearby molecules, which also vibrate as a result.

To know more about Frequency, visit-

https://brainly.com/question/14316711

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Select the correct answer

Which statement best supports the idea that water conservation is important for human societies?

OA Once humans use water, it cannot be reused ever again,

OB. Only about 1% of the freshwater on Earth is easily accessible.

OC Water is constantly being lost from the hydrosphere

OD. Most land animals use salt water instead of freshwater.

Answers

Answer:

Only about 1% of the freshwater on Earth is easily accessible.

Explanation:

Freshwater accounts for a minimal proportion of water resources on planet earth. About 70 percent of the world surface area  is covered by water, but only  about 2.5 percent of this mass of water is fresh. The remaining are marine or salt water. Amazingly, just about 1 percent of this  freshwater is easily accessible. The other 1.5% is trapped in glaciers and snowfields.

This underscore the need for water conservation on the planet since fresh water is a scarce resource and people living in many areas have no access to fresh water.

Describe Thomson’s and Millikan’s contributions to atomic theory.

Answers

Answer:

Thomson passed an electric current through sealed glass tubes filled with gases. Thomson concluded that electrons must be parts of the atoms of all elements. Millikan determined the charge and mass of the electron.

Explanation:

Thompson discovered electrons and proposed the plum - pudding model of the atom. Millikan measured the charge to mass ratio of an electron.

In the early days of the atomic theory, working with his cathode ray tube, J.J Thompson discovered electrons. His discovery of electrons led him to propose a model which depicted the atom as a sphere of positive charges into which negative charges were embedded. This is the plum-pudding model of the atom.

Using his famous oil-drop experiment, R.A Millikan successfully measured the charge to mass ratio of the electron and thereby determined the magnitude of charge on the electron.

Learn more: https://brainly.com/question/11527546


Calculate the energy of a photon with a frequency of 2.36 x 10-19 Hz.

Answers

Answer:

Explanation:

energy for photon is calculated in same wasy as for electromagnetic radiation

energy for electromagnetic radiation = hf

where f is the frequency of photon

h is Planck's constant = h = 4.14 × 10−15 eV · s.

thus

energy of photon = 4.14 × 10−15 eV · s *  2.36 x 10-19 Hz

energy of photon = 9.77 * 10−(-15+ -19) eV

energy of photon = 9.77 * 10−34eV        answer

What is the product of Na +CaSO4,

Answers

Answer:

Na + CaSO4 = Na2SO4 + Ca

Explanation:

single displacement (substitution)

Explain why warm air temperature has lower air pressure than cold air?

Answers

Answer:

Differences in temperature cause differences in air density. Warmer air is less dense than cold, which is why warm air tends to rise and cold air sinks.

temparature affects particles. warm particles are more spread out.

Explanation:

. Being acted on by gravity, colder, denser air weighs more and exerts greater pressure per unit area.

mL? PLEASEEE HELP
What is the answer

Answers

22.5 milliliters :)))
22.5 ml is the answer I think

I NEED THESE ANSWERED!!! PLEASEEE!!!!!

Answers

i will help you one second

what is the concept of the doppler effect?

Answers

Doppler Effect refers to the change in wave frequency during the relative motion between a wave source and its observer. ... For instance, when a sound object moves towards you, the frequency of the sound waves increases, leading to a higher pitch.

how this is helpful!!!!

IUPAC name for C3H7​

Answers

Answer:

propyl

Explanation:

......:)

..;) .........

A ball initially at rest is dropped from a window sill 14.2 m off the ground. Find the velocity of the ball the moment it hits the ground. Round your answer to 2 decimals places.

Answers

Answer:

16.68 m/s

Explanation:

The following data were obtained from the question:

Height (h) = 14.2 m

Initial Velocity (u) = 0 m/s

Final velocity (v) =?

Thus, the velocity (v) with which the ball hit the ground can be obtained as follow:

v² = u² + 2gh

NOTE: the acceleration due to gravity (g) = 9.8 m/s²

v² = u² + 2gh

v² = 0² + 2 × 9.8 × 14.2

v² = 0 + 278.32

v² = 278.32

Take the square root of both side

v = √278.32

v = 16.68 m/s

Therefore, the velocity with which the ball hit the ground is 16.68 m/s

how are subtances dissolved ?​

Answers

Answer: A solute dissolves because its particles interact with the particles of a solvent. Anything that allows more solvent to touch more solute will cause a solute to dissolve more quickly. Small pieces of a substance dissolve faster than large pieces.

A solute dissolves because its particles interact with the particles of a solvent. Anything that allows more solvent to touch more solute will cause a solute to dissolve more quickly. Small pieces of a substance dissolve faster than large pieces.

need help asap
Calculate the frequency for a wavelength of 635 nm.

Answers

Answer:

472114107.086614 MHz

Explanation:

f = C/λ

λ: Wavelength in meters

C: Speed of Light (299,792,458 m/s)

A substance absorbed 895 J and caused its temperature to increase by 10 ºC. If the substance has a mass of 27.9 g, what is the substance's specific heat in J/(gºC) ?

1.) 3.21

2.) 4.62

3.) 1,406.25

4.) 249,705

Answers

Answer:

i dont get the equation sorry wish i can help

4.62 is the correct answer

Which option is an example of a chemical property?
A. boiling point
B. ability to react with oxygen
C. color
D. density

Answers

Answer:

boiling point

Explanation:

Option B

please answer the “(fill-in)” ones thank you :)

Answers

Answer:

look

Explanation:

diffculte ou my good i need help too

With radiocarbon dating, scientists compare an object's carbon-14 levels with _____. the carbon-14 levels of an object from the same time period carbon-14 levels in the atmosphere the carbon-14 levels in the rock surrounding the object the object's carbon-12 levels

Answers

Answer:carbon-14 levels in the atmosphere

Explanation:

When carrying out radiocarbon dating, the level of carbon-14 in a sample is compared with the level of carbon 14 in the atmosphere because, objects exchange carbon-14 with the atmosphere.

Comparison of the activities of carbon-14 in the atmosphere and in the sample gives the age of the sample since the half-life of carbon-14 is a constant.

what can you infer about an ion that has a negative charge?

I NEED HELP FAST FOR MY TEST!!!

Answers

Answer:

It has more electrons than protons. It is an anion.

Lewis diagrams of molecules of three different hydrocarbons are shown above. Which of the following claims about the molecules is best supported by the diagrams?

Answers

Answer:

D

Explanation:

Seeing the Lewis formula for each of the molecules, we can attempt to write the condensed structural formula for each.

What we notice is that while there are purely single bonds between the carbon atoms in the first molecule, there is a double bond in the second molecule and a triple bond in the third

What we can deduce from this is that these are alkanes , alkenes and alkynes

The alkynes have the strongest of the three bonds and thus they have the strongest bonds in the mix

Since molecule 3 is an alkyne, then we can say that it has the strongest of the bonds

The correct claim about the molecules that best supports the diagrams is :

( D ) The strongest carbon to carbon bond occurs in molecule 3  

The first molecule ( molecule 1 ) is an alkane because the molecule is made up of only single bonds connecting the carbon atoms.

while the second mole ( molecule 2 ) is an alkene because of the presence of a double bond connecting carbon atoms.

and the third molecule ( molecule 3 ) is an alkyne because of the presence of a triple bond connecting carbon atoms.

Therefore  Alkynes have the strongest of of bonds between its carbon atoms  because of the presence of a triple connecting carbon atoms.

Hence we can conclude that The strongest carbon to carbon bond occurs in molecule 3

Learn more about alkynes : https://brainly.com/question/22138155

please need asap
An atom with 38 protons and 49 neutrons would be



Strontium-49


Francium-49


Strontium-87


Francium-87

Answers

Answer:

i think it is francium 87 if i fail then i am sorry

What is 8S8

In need for a quick answer

Answers

Answer:

8x8 Inc. is a provider of Voice over IP products. 8x8 products include cloud-based voice, contact center, video, mobile and unified communications for businesses.

Explanation:

CAN SOMEONE HELP ME!!!!!!!!!!!!!

Answers

Answer:

5 g/cm^3

Explanation:

Density = mass / volume

Using the formula M=dx v, Calculate the mass of a liquid with a density of
17.5 g/mL and a volume of 7mL.

Answers

Answer:

The answer is 122.5 g

Explanation:

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

mass = Density × volume

From the question

volume = 7 mL

density = 17.5 g/mL

We have

mass = 17.5 × 7

We have the final answer as

122.5 g

Hope this helps you

Plz help! :) :D I will mark you as BRAINLIEST!!!
Physical and Chemical Properties of Magnesium

Here is an EXAMPLE of how it has to be like. Instead of Mercury, you HAVE to do Magnesium

Physical Properties of Mercury: ”I’m a highly stable element, so you can count on me”

Chemical Properties of Mercury: ”I love to travel but I do corrode aluminum so we won’t be flying off on adventures in airplanes planes anytime soon”

Answers

Answer:

Some of the physical and chemical properties of magnesium are:

-The term ‘magnesium’ is derived from the Greek word magnesia, which refers to the name of the place from where it was extracted.

-Magnesium is closely related to manganese and magnetite.

-About 2.1% of the Earth’s crust contains magnesium. This makes magnesium the 6th most found element.

-The biggest deposits of magnesium is found in the seawater. It has been calculated by scientists that a cubic mile of seawater contains about 6 million tons of this element

2nd answer:

Physical Properties of Magnesium: ”I’m a highly stable element, so you can count on me”

Chemical Properties of Magnesium: ”I love to travel but I do corrode aluminum so we won’t be flying off on adventures in airplanes planes anytime soon

Explanation:

Hope this helps you out! UwU

PLEASE HELP!!
A model stands on a scale and finds her weight to be 105 pounds. If
the pressure exerted by her feet on the scale is 2.16 pounds per
square inch, what is the area of her feet in cubic centimeters?
__cm2

Answers

Answer:

313.5cm²

Explanation:

Given parameters:

Weight of model  = 105pounds

Pressure applied on the scale by model = 2.16pounds per square inch

Unknown:

Area of her feet in cm² = ?

Solution:

Pressure is the force per unit area;

     Pressure  = [tex]\frac{Force}{Area}[/tex]

Input the parameters and solve;

                2.16  = [tex]\frac{105}{Area}[/tex]

       105  = 2.16 x Area

        Area = [tex]\frac{105}{2.16}[/tex]   = 48.6in²

We need now to convert the in² to cm²

          1in² = 6.45cm²

        48.6in² = 48.6 x 6.45  = 313.5cm²

What large city in Texas will have its third day of rain?

Answers

Answer:

houston, texas

Explanation:

i hope this helps :)

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could someone please help me out on this? im confused Hatch Corporation's target capital structure is 40% debt, 50% common stock, and 10% preferred stock. Information regarding the company's cost of capital can be summarized as follows: The company's bonds have a nominal yield to maturity of 7%. The company's preferred stock sells for $40 a share and pays an annual dividend of $4 a share. The company's common stock sells for $25 a share and is expected to pay a dividend of $2 a share at the end of the year (i.e., D1 = $2.00). The dividend is expected to grow at a constant rate of 7% a year. The company has no retained earnings. The company's tax rate is 40%. What is the company's weighted average cost of capital (WACC)? [tex] \frac{100}{1000} = {10}^{x} [/tex] How do compounds differ from mixtures such as lemonade Paris's most famous landmark is the Eifel tower. Did you know the inventor built it for a competition and the judges thought it was weird? Write the equation of the line perpendicular to y=4x+2 and passes though the point (1,1). Solve for x.x+2/3=1/6Please help I'll give brainliest Is this correct?If the temperature is below the melting point the substance is a solidIf the temperature is above the boiling point the substance is a gasIf the temperature is in between the boiling and melting points the substances a liquid. Why was it important for the Americans to get support from Europeancountries during the Revolution Lauren earned $84 in 8 hourstoday. If she works the samehourly rate, how much moneywould Lauren make if sheworks 10 hours tomorrow? If a roof has a pitch of 5 to 11, how high will the roof rise over a 33-foot run?a.3C.272 feet1 feetb. 15 feetd.20 feet Sean began jogging to live a healthier lifestyle. On his first run, he ran one-half mile. He increased his workouts by adding two miles a month to his run. He wrote the equation f(x)= 0.5 + 2x to model his progress. The variable x represents the number ofmiles he runs.months he runs.miles he ran the first day.calories he burns 8 tomatoes for $2 unit rate I don't have much so please 17 please help me with this Which of the following best describes the structure of a nucleic acid? aCarbon ring(s) bGlobular or fibrous cSingle or double helix dHydrocarbon(s) Multiply. Write your answer as a fraction in simplest form.5/6(8/15)= Rewrite the following sentence correctly using colons and/or semicolons. I ordered many things at the restaurant a salad, chicken pesto, and tiramisu. Michael exercises more than 35 minutes per day.Use t to represent Michael's amount of exercise (in minutes per day). Indicate whether the following is a sentence or a fragment.She walked along the seashore.SentenceFragment Which example seems most like an informal discussion? a chat with friends about a TV show that aired last night a classroom conversation about a current events issue a teacher-student conference about an upcoming report a committee meeting in the conference room of an office