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3 years ago

Why there are only seven crystal systems??? why not other number

1 answer:

6 0

In crystallography, the terms crystal system, crystal family, and lattice system each refer to one ... In total there are seven crystal systems: triclinic, monoclinic, orthorhombic, ..... A polar crystal possess a "unique" axis (found in no other directions) such ... lattices in three dimensions; each can apply in one lattice system only.

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What is the mass of 0.100 mole of neon? (Watch sf’s)

dimaraw [331]

Answer:

The answer to your question is letter D. 2.02 g

Explanation:

Data

moles of Ne = 0.100

atomic mass of Neon = 20.18 g

Process

1.- Use proportions to find the answer

20.18 g of Ne ------------------ 1 mol of Ne

x ------------------ 0.1 moles

x = (0.1 x 20.18)/1

x = 2.018

2.- Consider the significant figures

0.100 has three significant figures so the answer must be 2.02 g

4 0

3 years ago

Read 2 more answers

Can u please help me I don't understand it and if I don't do it my teacher will get really mad at me pleas

Nana76 [90]

Physical Change: It is a type of change in which matter changes its physical state like shape, size but is not transformed into another substance. It is usually a reversible process.

Chemical Change: It is a type of change in which the rearrangement of atoms of one or more than one substance is involved. and it changes its chemical composition that is there is a formation of at least one new substance. It is usually an irreversible process.

Now, keeping in mind the definitions, we can easily classify the examples in the question as physical or chemical change.

7. Chemical Change

8. Chemical Change

9. Physical Change

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13. Chemical Change

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15. Chemical Change

16. Physical Change

17. Chemical Change

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19. Physical Change

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6 0

3 years ago

Arrange the following elements in order of decreasing metallic character.

Ivenika [448]

The arrangement of the elements in order of decreasing metallic character is: Rb, Zn, P, S, F, Ca, Co, Cr

<h3 /><h3>What are metals?</h3>

Metals are elements which are known by their special ability to form ions by a loss of electrons.

The increasing metallic character of metal is a measure of their ability to lose electrons.

Metallic character increases from right to left and down a group in the period table.

Metals are found to the left of the period table.

In conclusion, metals are known by their ability to lose electrons.

Learn more about metals at: brainly.com/question/25597694

#SPJ1

8 0

2 years ago

Plzz!!! I need help now this is science

Neko [114]

1)300-100=200N
2)300+100=400N
3)200+100-300=300-300=0N

5 0

3 years ago

A power plant is driven by the combustion of a complex fossil fuel having the formula C11H7S. Assume the air supply is composed

AlekseyPX

(a) 4C_11 H_7S + 55O_2 → 44CO_2 + 14H_2O + 4SO_2 + 20.68N_2;

(b) 4C_11 H_7S + 66O_2 → 44CO_2 + 14H_2O + 4SO_2 + 248.2N_2 + 11O_2;

(a) Balanced equation including N_2 from air

The balanced equation ignoring N_2 from air is

4C_11 H_7S + 55O_2 → 44CO_2 + 14H_2O + 4SO_2

Moles of N_2 =55 mol O_2 × (3.76 mol N_2/1 mol O_2) = 206.8 mol N_2

Including N_2 from air, the balanced equation is

4C_11 H_7S + 55O_2 → 44CO_2 + 14H_2O + 4SO_2 + 206.8N_2

(b) Balanced equation for 120 % stoichiometric combustion

Moles of O_2 = 55 mol O_2 × 1.20 = 66.00 mol O_2

Excess moles O_2 = (66.00 – 55) mol O_2 = 11.00 mol O_2

Moles of N_2 = 66.00 mol O_2 × (3.76 mol N_2/1 mol O_2) = 248.2 mol N_2

The balanced equation is

4C_11 H_7S + 66O_2 → 44CO_2 + 14H_2O + 4SO_2 + 248.2N_2 + 11O_2

Moles of O_2 required = 1700 kg C_11 H_7S

× (1 kmol C_11 H_7S/185.24 kg C_11 H_7S) × (55 kmol O_2/4 kmol C_11 H_7S)

= 126.2 kmol O_2

Mass of O_2 = 126.2 kmol O_2 × (32.00 kg O_2/1 kmol O_2) = 4038 kg O_2

Mass of N_2 required = 126.2 kmol O_2 × (3.76 kmol N_2/1 kmol O_2)

× (28.01 kg N_2/1 kmol N_2) = 13 285 kg N_2

Mass of air = Mass of N_2 + mass of O_2 = (4038 + 13 285) kg = 17 300 kg air

(d) Air:fuel mass ratio for 100 % combustion

Air:fuel = 17 300 kg/1700 kg = 10.2 :1

(e) Air:fuel mass ratio for 120 % combustion

Mass of air = 17 300 kg × 1.20 = 20 760 kg air

Air:fuel = 20 760 kg/1700 kg = 12.2 :1

6 0

3 years ago