Answer question number 4

Answer:

11

Explanation:

Answer:

amu = 34.055 or 34.1

Explanation:

to calculate the average mass, first convert the percentages into decimals. Then, calculate the mass numbers. To get this number, multiply the decimal by the mass number for each isotope and, then add them together.

( 0.315 x 32 ) + (0.685 x 35 ) = 34.055

NO can't  be used to fill a balloon

Conditions at T 0 ° C and P 1 atm are stated by STP (Standard Temperature and Pressure). At STP, Vm is 22.4 liters/mol.

Answer options that need to be added :

a. Ne

b. NO

c. NH₃

d. CH₄

e. HF

will float in air ⇒ element or compound to fill the balloon, its density must be less than < 1.285 g/L

We can use the ideal gas formula ta find density :

[tex]\tt \rho=\dfrac{P.MW}{RT}[/tex]

Because at STP, then the constant value is

[tex]\tt \rho=\dfrac{1~atm\times MW}{0.08205\times 273.15~K}\\\\\rho=0.0446\times MW[/tex]

So that the density is determined from the MW(molecular weight) of each element or compound

Ar = 20.1797 g/mol

[tex]\tt \rho=0.0446\times 20.1797=0.9~g/L[/tex]

MW=30.006 g/mol

[tex]\tt \rho=0.0446\times 30.006=\boxed{\bold{1.338~g/L}}[/tex]

MW=17.0306 g/mol

[tex]\tt \rho=0.0446\times 17.0306=0.760~g/L[/tex]

MW=16.04 g/mol

[tex]\tt \rho=0.0446\times 16.04=0.715~g/L[/tex]

MW=20.01 g/mol

[tex]\tt \rho=0.0446\times 20.01=0.892~g/L[/tex]

Answer:

A chemical bond is a lasting attraction between atoms, ions or molecules that enables the formation of chemical compounds. The bond may result from the electrostatic force of attraction between oppositely charged ions as in ionic bonds or through the sharing of electrons as in covalent bonds.

Explanation:

Answer:

the answer is C

Explanation:

i know this one, and may YOU PLEASE MARK BRAINLIEST I ONLY NEED ONE MORE CROWN TO MOVE TO THE NEXT RANK

The historical order of atomic models from the earliest to the most recent is as: Hard sphere model, electron shell model, and wave mechanical model. Therefore, option (A) is correct.

The atomic model can be described as the model used to describe the structure and composition of the atom. The atom as a primary component of matter has been under extensive study to understand the universe.

In the classical model of an atom, the atom is made of smaller particles with an electrical charge called electrons, protons, and neutrons. To understand the atomic models, it is important to understand how these particles make up the atom.

There are five principal atomic models that have been proposed over time,  which are Dalton’s atomic model, Thomson’s atomic model, Rutherford’s atomic model, Bohr’s atomic model, and the quantum atomic model.

Learn more about the atomic model, here:

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Your question was incomple, most probably the complete question was,

Which group of atomic models is listed in historical order from the earliest to the most recent?

A)  Hard sphere model, electron shell model, and wave mechanical model

B)  Hard sphere model,  wave mechanical model, and electron shell model

C) Electron shell model, Hard sphere model, and wave mechanical model

D) Electron shell model, wave mechanical model, and  Hard sphere model

Answer:

d = 2.8 g/mL

Explanation:

Given data:

Mass of sample = 67.9 g

Volume of water = 28.0 mL

Volume of water + sample = 52.0 mL

Density of sample = ?

Solution;

Density is equal to the mass of substance over volume of substance.

Formula:

d = m/v

d = density

m = mass

v= volume

Now we will calculate the volume of sample.

Volume of sample = (volume of water+ sample) - volume of water

Volume of sample = 52.0 mL - 28.0 mL

Volume of sample = 24.0 mL

Now we will calculate the density.

d =67.9 g /24.0 mL

d = 2.8 g/mL

Answer:

Mass = 0.000176 gram

Steps:

m =  V × ρ

=  20 milliliter × 8.8 gram/cubic meter

=  2.0E-5 cubic meter × 8.8 gram/cubic meter

=  0.000176 gram

Explanation:

Answer:

Elements that are metals tend to lose electrons and become positively charged ions called cations. Elements that are nonmetals tend to gain electrons and become negatively charged ions called anions. Metals that are located in column 1A of the periodic table form ions by losing one electron.

Explanation:

hope it helps!

During electrolysis a metal chemically decompose and deposits on the cathode where as the metal from the other electrode forms its ions in the electrolyte solution.

Electrolysis is the process of chemical decomposition brought out by the passage of electricity through an electrolyte in which the decomposed metal deposits on one electrode.

Electrolysis involves oxidation of one metal and reduction of the other. The prediction of the products of electrolysis requires a consideration of several factors including the potential at which the competing species are discharged at the electrode , if the electrode used are reacted or inert etc.

The oxidation reaction involves the formation of cations in the solution and the reduction involves the deposition of metallic substance at the cathode.

To find more on electrolysis, refer here:

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Answer:

Explanation:

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

From the question

volume = 2.45 mL

density = 4.255g/mL

We have

mass = 2.45 × 4.255 = 10.42475

We have the final answer as

Hope this helps you

Answer:

=0.00123

Explanation:

Look at the attachments below

Hope this helps (:

Answer:

0.00123

Explanation:

Standard notation is the normal way of writing numbers. Examples include 1, 2, and 10. The number 1.23 x 10^-3 is written in scientific notation. The decimal goes after the first nonzero integer and it is multiplied by a power of 10. The power or exponent attached to the 10 tells you how many places over you need to move the decimal to get back into scientific notation. Examples include 1.00 x 10^2 (representing 100 in standard form because you would move the decimal two places to the right.), 2.0 x 10^1 (representing 20 in standard form because you would move the decimal one place to the right), and 3.0 x 10^-4 (representing 0.0003 in standard form because you would move the decimal four places to the left since it is a negative exponent).

The negative (-3) exponent in 1.23 x 10^-3 indicated to move the decimal three places to the left. If it was positive, you would move it three places to the right.

In 1.23 x 10^-3 move the decimal to the left 1 place to get:

0.123

two places to get:

0.0123

and a third place to get:

0.00123

The final answer is 0.00123

Answer:

20

Explanation:

Answer:

Explanation:

1=i

4=d

5=m

6=c

8=o

9=j

10=a

13=b

14=h

15=l

Theses are the ones i knew

Answer:

Follows are the solution to this question:

Explanation:

The characterization with water molecules would be that light waves are made up of 2 different types of atoms (2 hydrogen and 1 oxygen atoms), as per the Dalton theory. There are many multiple times as many atoms of hydrogen as oxygen atoms in each water molecules. For every two hydrogen atoms, all water molecules have one oxygen atom.

Answer:

Sample Response: Dalton’s theory about compounds tells us that all water molecules have different kinds of atoms, two hydrogen atoms for every one oxygen atom.

Explanation:

Answer:

mechanical or kinetic eg hammer and nails

Answer:

95% of the time (or any other percentage you choose), the electron will be found within a fairly easily defined region of space quite close to the nucleus. Such a region of space is called an orbital. You can think of an orbital as being the region of space in which the electron lives

Answer:

The penny now weighs 0.0025kg

Hope this helps please give me brainliest!

God bless!

Answer:

Explanation:

This should be in physics.

d = 100 meters south

t = 13 seconds

v = d/t

v = 100 / 13

v = 7.69 m/s going south.

The point is that you have to specify the direction.

Answer:

Earth is in the solar system.

Explanation:

Earth is our home and it is in the solar system.

Earth is the fifth-largest of the planets in the solar system and the third planet from the sun. Earth is the only planet having oxygen and water that supports life. Till now according to the research Earth is the only planet having life.

Planets are in the solar system, the solar system is in the milky way and the milky way is present in the universe. The astronomer identifies our home in the universe as "Earth is in the solar system" as Earth is our home.

Hence, the correct answer is "Earth is in the solar system."

Answer:

The Milky Way is in the universe. The solar system is in the Milky Way. Earth is in the solar system.

Explanation:

If the Milky Way Is in the universe and solar system you would know earth is also In the solar system, so "Our home planet is the third planet from the Sun, and the only place we know of so far that's inhabited by living things. While Earth is only the fifth largest planet in the solar system, it is the only world in our solar system with liquid water on the surface."

Answer:

Mendeleev realized that the physical and chemical properties of elements were related to their atomic mass in a 'periodic' way, and arranged them so that groups of elements with similar properties fell into vertical columns in his table.

Explanation:

google

Answer:

0.013g/cm^3

Explanation:

density= mass÷volume

Answer:

0.01(3) g/cm3 (cm3 means centimeter cubed, (3) means the 3 goes on forever)

Explanation:

The volume of the sheet is 300 cm3, and dividing 4 grams by 300 cm3 gets you 0.01(3) g/cm3. Hope it helps!

Answer:

small molecules move into the cell, Then it is by diffusion or facilliated diffusion.

4.94 x c . (Tm-23.6)=C.(23-6-21.9)+123.13 x c. (23.6-21.9)

The law of conservation of energy can be applied to heat changes, ie the heat received/absorbed is the same as the heat released  

Q in = Q out  

Heat can be calculated using the formula:  

Q = mc∆T  

A calorimeter is a device used to measure the specific heat of material  

A metal is put into a calorimeter that contains water and there will be heat transfer:  

[tex]\tt \displaystyle m_mc_m (T_m-T)=m_wc_w(T-Tw)[/tex]

m = metal  

w = water  

T = the final temperature of the mixture  

mass of metal =(Nickel) = 4.94 g

mass of calorimeter = 12.5 g

mass of water = 123.13 g (135.63 - 12.5)

The equation

Q released (metal) = Q absorbed(calorimeter+water)

The equation :

4.94 x c . (Tm-23.6)=C.(23-6-21.9)+123.13 x c. (23.6-21.9)

Answer:

Phosphorus trioxide

Explanation:

Answer:

Tetraphosphorus hexoxide

Explanation:

Give brainliest please

Answer:

According to google, "About five million million hydrogen atoms could fit. Some factors would affect that number like the area of the head and the size of atoms (as well as attractions between atoms). Some atoms are larger than others." Is this accurate? I'm not sure. Good luck! :)

Answer:

9429.9

Explanation:

periodt