1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
wariber [46]
2 years ago
7

.The 1" row of the periodic table has which two elements?

Chemistry
1 answer:
zlopas [31]2 years ago
5 0

On the periodic table, hydrogen and helium are the only two elements in the first row, or period, which reflects that they only have electrons in their first shell. Hydrogen and helium are the only two elements that have electrons exclusively in the 1 s 1s 1s orbital in their neutral, non-charged, state.

You might be interested in
HELP ASAP
sergejj [24]

D- A molecule

Explanation:

(Apex)

3 0
2 years ago
Which of the following pure liquids is the best solvent for sodium fluoride?a. CCl4b. C2C6c. HCld. BCl3e. PCl5
Julli [10]

Answer:

HCl

Explanation:

The best solvent for NaF is a polar liquid. The only liquid having a significant dipole moment among the options is HCl due to the large electro negativity difference between hydrogen and chlorine.

The polar solvent can interact with the NaF via its dipoles such that the NaF dissolves due to ion-dipole interaction.

4 0
3 years ago
Five kg of carbon dioxide (CO2) gas undergoes a process in a well-insulated piston-cylinder assembly from 2 bar, 280 K to 20 bar
kaheart [24]

This question is incomplete, the complete question is;

Five kg of carbon dioxide (CO2) gas undergoes a process in a well-insulated piston-cylinder assembly from 2 bar, 280 K to 20 bar, 520 K. If the carbon dioxide behaves as an ideal gas, determine the amount of entropy produced, in kJ/K. Assuming;

a) constant specific heats Cp = 0.939 kJ/Kg K

b) variable specific heats

Answer:

a) the amount of entropy produced is 0.731599 kJ/K

b) the amount of entropy produced is 0.69845 kJ/K

Explanation:

Given the data in the question;

5 kg of carbon dioxide (CO₂) gas undergoes a process in a well-insulated piston-cylinder assembly.

m = 5 kg

Molar mass M = 44.01 g/mol

P₁ = 2 bar, P₂ = 20

T₁ = 280 K, P₂ = 520 K

Since its insulated { q = 0 } ( kinetic and potential energy effects = 0 )

Now,

a) the amount of entropy produced, in kJ/K, Assuming constant specific heats with Cp = 0.939 kJ/Kg K

S_{Generation = m × ((Cp × In( T₂/T₁) - R × In( P₂/p₁ ))

we substitute

S_{Generation = 5 × (( 0.939  × In( 520/280) - 0.1889 × In( 20/2 ))

= 5 × ( 0.5812778 - 0.434958 )

= 5 × 0.1463198

= 0.731599 kJ/K

Therefore, the amount of entropy produced is 0.731599 kJ/K

b) the amount of entropy produced, in kJ/K, Assuming variable specific heats.

Now, from  Table A-23: Ideal Gas Properties of Selected Gases;

T₁,T₂ : s₁⁰ = 211.376 kJ/kmol-K, s₂⁰ = 236.575 kJ/kmol-K

now, s₁ = s₁⁰ / M and s₂ = s₂⁰ / M

we substitute

s₁ = s₁⁰ / M = 211.376 / 44.01  = 4.8029 kJ/kg

s₂ = s₂⁰ / M = 236.575 / 44.01 = 5.37548 kJ/kg

S_{Generation = m × (( s₂ - s₁ ) - R × In( p₂ / p₁ ))

we substitute

S_{Generation = 5 × (( 5.37548 - 4.8029  ) - 0.1880 × In( 20 / 2 ))

= 5 × ( 0.57258 - 0.432885997 )

= 5 × 0.13969

= 0.69845 kJ/K

Therefore, the amount of entropy produced is 0.69845 kJ/K

5 0
2 years ago
How many grams of solute are needed to prepare a 3.50% mass/mass solution that has a solution mass of 2.50x102 grams.
Elis [28]
One way of expressing concentration is by percent. It may be on the basis of mass, mole or volume. Percent is expressed as the amount of solute per amount of the solution. For this case, we are given the percent by mass. In order to solve the amount of solute, we multiply the percent with the amount of the solution.

Mass of solute = percent by mass x mass solution
Mass of solute = 0.0350 x 2.50 x10^2 = 8.75 grams of solute
5 0
3 years ago
The organic compounds that are divided into two types, simple and complex, are called _____.
Sati [7]

The organic compounds that are divided into two types, simple and complex, are called carbohydrates.

Carbohydrates are diveded into twy types: simple and complex (starches, fiber, glycogen).

Simple carbohydrates are made of one (monosaccaharides) or two sugar units.

Complex carbohydrates are made up of many sugar units.

For example, glucose (C₆H₁₂O₆) is a simple carbohydrate.

Glucose is chemical compound composed of six carbon atoms, twelve hydrogen atoms and six oxygen atoms.

Starch is a polymeric carbohydrate consisting of a large number of glucose units bonded by glycosidic bond. Starch is a white, tasteless and odorless powder that is insoluble in cold water or alcohol.

More about carbohydrates: brainly.com/question/20290845

#SPJ4

6 0
1 year ago
Other questions:
  • URGENT HELP! I dont understand anything of this and this is for tomorrow
    9·1 answer
  • Agar is used to culture bacteria and as a medium in electrophoresis. The agar used in this Petri dish is a by-product of an unli
    13·1 answer
  • In general, an atom with _________________ electrons in its valence shell tends to lose electrons and form a ___________________
    15·1 answer
  • The Hp scale is a measurement system that indicates the concentration of in solution?
    5·1 answer
  • _____ is a gel-like substance enclosed by the cell membrane that contains the cell's organelles. A) chloroplast B) cytoplasm C)
    6·2 answers
  • 1. Using the balanced equation, answer the following questions:
    15·1 answer
  • What are the properties of elements??​
    15·2 answers
  • What is Metabolism?
    15·2 answers
  • Which of the following is not true
    14·1 answer
  • 1. What did Henri Becquerel discover about<br> radiation emitted from uranium salts?
    8·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!