The measurement 0.01011 km has how many significant figures?

Answer:

The mass number of the atom is equal to the sum of the number of protons and neutrons in the nucleus

Explanation:

Each proton and each neutron weigh one amu( atomic mass unit), adding together the neutrons and protons and multiplying by 1 amu you get the mass of an atom

Answer:

The balanced equation is given below:

4Fe + 3O2 —> 2Fe2O3

Explanation:

Fe + O2 —> Fe2O3

The above equation can be balance by doing the following:

Fe + O2 —> Fe2O3

There are 2 atoms of O on the left side and 3 atoms on the right side. It can be balance by putting 3 in front of O2 and 2 in front of Fe2O3 as shown below:

Fe + 3O2 —> 2Fe2O3

There are 4 atoms of Fe on the right side and 1 atom on the left side. It can be balance by putting 4 in front of Fe as follow:

4Fe + 3O2 —> 2Fe2O3

Thus, the equation is balanced

Answer:

i think the forces are the same and size and in opposite directions

Explanation:

Answer:

I think it should be

The forces are the same size and in opposite directions

Explanation:

because newtons third law is applied equal force but opposite

Answer:

10000000

Explanation:

Use wave equation: c=frequency * wavelength

c=3.00*10^8 m/s

Thus,

[tex]\frac{3.00*10^{8} }{30}[/tex]=10000000

Answer:

electronegativity

Explanation:

Answer:

THe tendoncy is electronegstivity

Explanation:

Im a big brain person

Answer:

B

Explanation:

Answer:

N2.

Explanation:

The words that complete the blanks are;

1) transverse waves

2) the ground

3) medium

We know that a wave is simply the kind of disturbance that moves along a medium and in the process there is a transfer of energy from one point to another. There are various kinds of waves and the classification of the waves is based on the amount of energy that is transferred in each case.

1) We know that in the case of the light waves, the direction of the wave is perpendicular to the motion of the particle that causes the wave as such we can all it a transverse wave.

2) We know that a wave must always involve an energy that is travelling and in this case, the energy is travelling through the land and this is the ground.

3) We know that the mechanical waves must have to move through a medium of propagation. As such, mechanical waves must move through a medium.

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Answer:

moles H = 2 x 0.0649=0.130

ions = 0.130 x 6.02 x 10^23=7.81 x 10^22

Explanation:

Answer: Selenium is a member of the sulfur family with elements including tellurium and polonium. This family has six electrons in the outermost shell. Selenium specifically has an electron configuration of 2-8-18-6. The six electrons in the outermost shell allow selenium to have a variety of valence numbers.

Explanation:

Answer:

Explanation: It’s the correct answer on Edmentum.

Answer:

the formula for mass number is "mass number = protons + neutrons".

Answer:

I think its b

Explanation:

Sorry if wrong! Hope this helps tho! maybe mark me brainliest if I am?

N2 + 3 H2 = 2 NH3

Reaction type: synthesis

Answer:

nonmetel

Explanation:

Answer:

Its a non-metal

Explanation:

Elements that tend to gain electrons to form anions during chemical reactions are called non-metals. These are electronegative elements. They are non-lustrous, brittle and poor conductors of heat and electricity (except graphite). Non-metals can be gaseous, liquids or solids.

Answer:

ΔT = 0.843 °C

Explanation:

Given data:

Heat added = 0.484 J

Mass of water = 0.1372 g

Temperature increase = ΔT = ?

Solution:

Formula:

Q = m.c. ΔT

Q = amount of heat absorbed or released

m = mass of given substance

c = specific heat capacity of substance

ΔT = change in temperature

Specific heat capacity of water is 4.184 j/g.°C

Now we will put the values in formula.

0.484 j = 0.1372 g × 4.184 j/g.°C× ΔT

0.484 j = 0.574j/°C× ΔT

ΔT = 0.484 j / 0.574j/°C

ΔT = 0.843 °C

Answer:

reacts in air to form a green layer

Explanation:

Properties of substances can be physical or chemical. A physical property is that which does not affect the chemical composition of the substance(s) involved e.g melting point, boiling point, color, state of matter as depicted for copper (Cu) in this question.

On the other hand, chemical property of a substance are those properties that alters or affects the chemical composition of the substance. In other words, they are features that can be observed after the substance has undergone a chemical reaction. In this question, COPPER REACTING IN AIR TO FORM A GREEN LAYER IS A TYPE OF CHEMICAL PROPERTY because a chemical reaction has occured with the evidence of the green layer formation.

Answer:

it is 52.7

Explanation:

so when it is 30 the degree is 5°

when it is 60, the degree is 10°

when it is 90, the degree is 15° and so on...

Answer:

T₂ = 695.33 K

Explanation:

Given data:

Initial volume = 150 mL

Initial temperature = 25°C (25+273 = 298 K)

Final temperature = ?

Final volume = 350 mL

Solution:

The given problem will be solve through the Charles Law.

According to this law, The volume of given amount of a gas is directly proportional to its temperature at constant number of moles and pressure.

Mathematical expression:

V₁/T₁ = V₂/T₂

V₁ = Initial volume

T₁ = Initial temperature

V₂ = Final volume  

T₂ = Final temperature

Now we will put the values in formula.

V₁/T₁ = V₂/T₂

T₂ = V₂T₁ /V₁

T₂ = 350 mL × 298 K / 150 mL

T₂ = 104300 mL.K / 150 mL

T₂ = 695.33 K

Answer:

You can get 7 answers wrong.

Explanation:

Let's calculate the average

[tex]\frac{15}{2} \\\\=7.5[/tex]

So if you correctly answer 8 -15  (7.5 is approximated to 8 )questions correctly you will pass.

So you can get 7 answers wrong.

Answer:

The one on the top,'' As the water cool, it is returned to the boiler where it is heated,''

Explanation:

Answer:

X represents barium - 141 nucleus.

Written as: (141, 56) Ba

Explanation:

In nuclear fission reaction, due to the fact that the process produces more neutrons, a nuclear chain reaction can possibly occurr. Now, a chain reaction is a one whereby the material that begins the reaction will also be one of the products and it can start another reaction.

Now, for the nuclear chain reaction for the fission of uranium-235, its nucleus absorbs a neutron after which it splits into a krypton - 92 nucleus and a barium - 141 nucleus. Thereafter it releases three more neutrons.

Thus, X is the image represents barium - 141 nucleus.

(141,56) Ba

Answer:

Explanation:

7.706 g of CO₂ will contain 12 x 7.706 / 44 g of C

= 2.1 g of C .

This will be contained in 3.256 g of isopentyl acetate

3.156 g of H₂O will contain 2 x 3.156 / 18 g of H

= .351 g of H

This will be contained in 3.256 g of isopentyl acetate

Rest will be oxygen

amount of oxygen in 3.256 g of isopentyl acetate

= 3.256 - ( 2.1 + .351 )

= .805 g

ratio of C , H , O in isopentyl acetate

= 2.1 g : .351 g : .805 g

2.1 / 12 : .351 / 1 : 0.805 / 16 ratio of moles

= .175 : .351 : .05  ratio of moles

= 3.5 : 7.02: 1

= 7 : 14 : 2

empirical formula of  isopentyl acetate

= C₇ H₁₄ O₂ .

Answer:

5

Explanation:

Answer:

1. The volume of displaced fluid is equivalent to the volume of an object fully immersed in a fluid or to that fraction of the volume below the surface of an object partially submerged in a liquid. The weight of the displaced portion of the fluid is equivalent to the magnitude of the buoyant force.

Why would you use this method?

So it can be used to accurately measure the volume of the human body and other oddly shaped objects by measuring the volume of fluid displaced when the object is submerged.

2. Density, mass of a unit volume of a material substance. The formula for density is d = M/V, where d is density, M is mass, and V is volume. Density is commonly expressed in units of grams per cubic centimetre.

What happens to things that are denser?

Students should realize that if an object weighs more than an equal volume of water, it is more dense and will sink, and if it weighs less than an equal volume of water, it is less dense and will float.

What happens if they are less dense?

The density of an object determines whether it will float or sink in another substance. An object will float if it is less dense than the liquid it is placed in. An object will sink if it is more dense than the liquid it is placed in.

Ok thanks for the valuble info.

Answer:

What mass of silver will raise the level of the water in the graduated cylinder 1.50 mL? (Ans) 28.95 g / 1.50 mL = 19.3 g/mL (The gold's density)

19.3 gm/ml³ is the density of gold  .

Density, mass of a unit volume of a material substance. Density of a substance tells how close the particles of a substance are packed.

The formula for density is D = M/V, where d is density, M is mass, and V is volume.

Density is commonly expressed in units of grams per cubic centimeter.

The SI unit of density is kilogram per cubic meter (kg/m3).

It is also represented  in the c g s unit of grams per cubic centimeter (g/cm3).

To calculate density of gold (here):

Given,

Mass of gold=28.95 gm

Volume of water=1.50 mL

Density=?

Density =Mass/Volume

Density=28.95/1.50

Density=19.3 gm/ml³

Hence, 19.3 gm/ml³ is the density of gold .

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Answer:

There are many ways to figuring this out: you could use a ruler, a calculator or scrap paper.

Explanation:

This is not an actual flat out answer, but it’s helpful methods to getting the answer the next time you are stuck. Hope you are having a nice day. Bless your heart and soul.

Answer:

Group 2 is the correct answer.

Explanation:

Chlorine has a charge -1. It means that X is +2 so that the formula is XCl2.