Explain how you know it must be oxygen. Where did the oxygen come from?

Answer: freezing point of water 273.15K, boiling point of water 373.15 K

Explanation:

The Kelvin scale starts at the lowest possible temperature, absolute zero. This is 0 Kelvins (K)= -273.15 deg C. Hence water freezes at 0 deg C = 273.15 K and boils at 100 deg C = 373.15 K

Answer:

I think it might be 2 miles per hour

Answer:

They are so small that they barely make up any of the mass of the atom, and they are so miniscule that during Rutherford 's Gold foil experiment ,they didn't even react with the alpha particles. They circle the nucleus on a ring. shown through Rutherford Atomic Model

hope it helps you

Answer:

See explanation

Explanation:

Polymerization refers to the formation of a macro-molecule by the aggregation of small molecules called monomers. Monomers are the small molecules that are joined together to form a polymer.

The formation of a condensation polymer is accompanied by the loss of a small molecules such as water as shown in the image attached.

Succinic acid reacts with ethylenediamine to form a nylon type polymer. The nature of this reaction is detailed in the image attached to this answer. Recall that a polymer may contain (n) number of monomers joined together in the macromolecule.

When a solid turns into a liquid

Example: Ice cube melts into water

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Answer:inner Diameter =9.19cm

Explanation:

Density is calculated as Mass/ Volume

therefore

Volume= Mass/ Density = 1360g/ 0.953g/ml=1,427 ml

1ml = 1cm³

1,427ml = 1,427cm³

Also We know that Volume of a cylinder = πr²h or  πr²l

1,427cm³ = 3.142 x r² x 21.5 cm

 r² =  1,427cm³/ (3.142 x 21.5cm)

r² =21.124cm²

[tex]\sqrt{21.124}[/tex]= r²

r= 4.596cm

Diameter=  2 x radius

=2 x 4.596

=9.19cm

Answer:

1.00 mole of any element has a mass numerically equal to its atomic mass in grams and contains 6.022×1023 particles.

Answer:

1- Hélium

2-protons

3-Electrons

4-2

Respectively thx

Answer:

221g is the mass of the bar of aluminum

Explanation:

The volume of a bar of aluminum is obtained as:

Length*Width*height = Volume

That means the volume of the bar is:

2.03cm * 3.0056cm * 13.4cm = 81.8cm³

Now, the density of 2.70g/cm³ means the aluminum weighs 2.70g per cm³. The mass of 81.8cm³ is:

81.8cm³ * (2.70g / 1cm³) =

Answer:

84.6g of nitrogen is the mass dissolved in a home aquarium

Explanation:

Using combined gas law:

PV = nRT

We can solve for the mass of nitrogen solving the total moles of the aquarium and with the mole fraction as follows:

P = 1.0atm

V = 93.0L

R = 0.082atmL/molK

T = 20°C + 273.15 = 293.15K Assuming room temperature as 20°C

PV / RT = n

1.0atm*93.0L / 0.082atmL/molK*293.15K

3.87 = moles of gas

As mole fraction of nitrogen in the air is 0.78, moles of nitrogen are:

3.87 * 0.78 = 3.02moles of nitrogen

As molar mass of nitrogen gas, N₂, is 28g/mol:

3.02 mol N₂ * (28g / mol) =

Answer:

D earth formed 4.5 billion years ago.

Answer:

18m/s

Explanation:

Given parameters;

Initial velocity  = 10m/s

Acceleration  = 2m/s²

Time = 4s

Unknown:

Car's new velocity  = ?

Solution:

We use one of the kinematics equation to solve this problem:

          v  = u + at

v  = new velocity

u = initial velocity

a = acceleration

t = time

      v = 10 + (2 x 4)  = 18m/s

Answer:

Potassium

Explanation:

From the given riddle. Potassium is the right answer. This because on the periodic table, potassium has the smallest atomic number of any element in its period with the electronic configuration 1s2 2s2 2p6 3s2 3p6 4s1, it has the largest atomic radius within its group because the radius has no d-electron shell filled. Potassium is a soft metal but contains high reactivity.

Explanation:

Cholesterol concentration = 27 mg/ 232 mL

Change unit mg/ml to kg/m³

1 kg = 1000 g

1 g = 1000 mg

1 kg = 1000000 mg

1 kg = 10⁶ mg

10⁶ mg = 1 kg

1 mg = 10^-6 kg

m³ = 1000 L

1 L = 1000 mL

m³ = 1000000 mL

m³ = 10⁶ mL

10⁶ mL = m³

1 mL = 10^-6 m³

Cholesterol concentration = 27 mg/ 232 mL

27 × 10^-6 kg/ 232 × 10^-6 m³

= 27/232 kg/m³

Answer:

482.2 ft.

Explanation:

Hello!

In this case, considering that Charlotte drives at 69.8 mi/h, the first thing we need to do is to convert that velocity to ft/s as shown below:

[tex]69.8\frac{mi}{h}*\frac{5280ft}{1mi} *\frac{1h}{3600s}=102.37\frac{ft}{s}[/tex]

Thus, the travelled distance is obtained by multiplying the new velocity by the elapsed time:

[tex]d=102.37\frac{ft}{s} *4.71s\\\\d=482.2ft[/tex]

Best regards!

Answer:

single replacement

Explanation:

I took the test :)

Cl₂ + 2KI → 2KCl + I₂ is an example of single replacement reaction. Therefore, option D is correct.

A single-replacement reaction is a chemical reaction in which one element replaces by the another in a compound. The general equation is. A + BC ⇒ AC + B.

An example of a single replacement reaction occurs when the element potassium  reacts with water, then the colorless solid compound  potassium hydroxide formed, and hydrogen gas is release. The equation for this reaction is as follows:

2K + 2H2O ⇒ 2KOH + H.

There are three main types of single replacement reactions are metal replacement, hydrogen replacement and halogen replacement reaction.

Thus, option D is correct.

To learn more about single replacement reaction, follow the link;

https://brainly.com/question/13903783

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Answer:

                                    Organizing a Birthday Party

On 20 June I was born and every year me and my parents celebrate my birthday in our house. But, This time I had an idea to organize my birthday  party in a Big Hall where all my classmates and society friends will join me and we'll play lots of games and Have an amazing party.

So, I discussed my this idea with my father and he said "Okay, we'll celebrate your birthday this time as you wish". Then I took help from my GrandPa to send out invitation cards to my friend's and my father was going to book a Big Party Hall in 'The Calves Restaurant' where we will celebrate my birthday and my mother helped me in getting game ideas which we will play on the birthday.

On Birthday (20th June), when everybody arrived one of my friend sang a beautiful Birthday song from me. Then I blew out the candles off the cake. We also had games like Ludo, carrom, passing pillow, musical chair, and etc. At the end we had DJ where all my friends and my family members enjoyed. This was an amazing party to everyone.

Explanation:

Hey, if I solved your problem then please give rating to my answer and mark me as brainlist.

Thank-you,

Answer:

B

Explanation:

Meiosis ensures that the sperm and egg contain only 50-50.10% of the chromosomes of an organism.

Answer:

28.085

Explanation:

The formular to obtain average atomic mass unit from isotopes is given as;

sum of (Percentage abundance * Atomic mass) of all isotopes =  Average atomic mass unit

Silicon 28 = 92.23%

Silicon 29 = 4.67%

Silicon 30 = 3.1%

(92.23 / 100  *  27.977) + (4.67 / 100  *  28.976)  +  (3.1 / 100  * 29.974) = Average atomic mass

Average atomic  mass = 25.803 + 1.353 + 0.929 = 28.085

Answer:

They are both in the nucleus of an atom, they have different charges

Explanation:

Protons and neutrons are similar because they are both in the nucleus of the atom, being orbited by the electron(s). They are different, however, because they have different charges, the proton is positively charged and the neutron is neutral.

hope this helped:)

Explanation:

First, you need to be sure the elemental analysis has identified all the components.

83.7+16.3=100% so we’re good, and the same ratio works for the formula,

The formula is CxHy, so x*12+y*1= 100% of the empirical formula wt, which we’ll use later to confirm the elemental analysis. We need x and y

Then x = 83.7/12 is 6.975 and being savvy, we guess it’s supposed to be 7, since empirical formulas use whole numbers if they can. Likewise y=16.3/1 = 16.3, and now we round down to the nearest whole number (16), making our empirical formula C7H16

Check:

7*12+16*1=100 (the empirical formula wt) 84/100=0.84 and 16/100=0.16 This is close enough, so C7H16 is the empirical formula.

Answer:A separating funnel is funnel that is used to separate immiscible liquids. Liquids that do not mix with each other are said to be immiscible. Two immiscible liquids, such as oil and water, can be separated by using a separating funnel.

Explanation:

Answer:

Immisicible liquids

Explanation:

A separating funnel is funnel that is used to separate immiscible liquids. Liquids that do not mix with each other are said to be immiscible. Two immiscible liquids, such as oil and water, can be separated by using a separating funnel.

Answer:

Moore's Law refers to Moore's perception that the number of transistors on a microchip doubles every two years, though the cost of computers is halved. Moore's Law states that we can expect the speed and capability of our computers to increase every couple of years, and we will pay less for them.

Answer:

Four hydrogen atoms are present

Answer:

(4) A bond is formed as energy is released.

Explanation:

Quizlet

A bond is formed as energy is released best describes the energy change in

the reaction.

Hydrogen atoms share their electrons to form a hydrogen molecule( H₂) .

Covalent bonds are the types of bonds formed when it occurs.

The formation of the bond results in energy being released. On the other

breaking of bonds involves energy to be absorbed. The stated facts

confirms  D as the most appropriate choice.

Read more on https://brainly.com/question/1853488

Answer: The mass of the ethanol is 322.6 pounds

Explanation:

Density is defined as the mass contained per unit volume.

[tex]Density=\frac{mass}{Volume}[/tex]

Given : Mass of ethanol = ?

Density of ethanol= [tex]0.789g/ml[/tex]

Volume of ethanol = 49.0 gal = 185485 ml    ( 1gal=3785ml)

Putting in the values we get:

[tex]0.789g/cm^3=\frac{xg}{185485ml}[/tex]

[tex]x=146347g=322.6pound[/tex]         (1g=0.00220462pound)

Thus the mass of the ethanol is 322.6 pounds