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
insens350 [35]
3 years ago
11

PLEASE HELP ME :( It’s urgent!!!!!

Chemistry
1 answer:
MrRa [10]3 years ago
5 0

Answer:

C and D

Explanation:

In the first table, both element particles have more electrons than protons which is unusual and indicates they have a negative charge. Furthermore both numbers add up to full electron shells (2,8 and 2,8,8) meaning they are ions (charged particles formed to gain full valence shells and become stable), so it is C for the first question, negative ions.

As for the second one, isotopes like versions of the same element except with different numbers of neutrons, so they are still the same element but have different mass. As shown here the numbers indicate the number of neutrons therefore it is D, 3 more neutrons and no more electrons.

Hope this helped!

You might be interested in
A sample of mass 6.814 grams is added to another sample weighing 0.08753 grams.
Feliz [49]

Answer:

17.5609g

Explanation:

According to the question, a sample of mass 6.814 grams is added to another sample weighing 0.08753 grams. That is weight of sample 1 + weight of sample 2;

6.814 + 0.08753 = 6.90153grams

Next, the subsequent mixture is then divided into exactly 3 equal parts i.e. 6.90153grams divided by 3

= 6.90153/3

= 2.30051grams.

One of the equal parts is 2.30051grams, which is then multiplied by 7.6335 times I.e. 2.30051 × 7.6335 = 17.5609grams

Therefore, the final mass is 17.5609grams

3 0
3 years ago
If 63.8 grams of aluminum metal (Al) react with 72.3 grams of sulfur (S) in a synthesis reaction, how many grams of the excess r
Jobisdone [24]

Answer:

23.2 g of Al will be left over when the reaction is complete

Explanation:

2Al  +  3S  → Al₂S₃

1 mol of Al = 26.98 g

1 mol of S = 32.06 g

Mole = Mass / Molar mass

63.8 g/ 26.98 g/m = 2.36 mole of Al

72.3 g / 32.06 g/m = 2.25 mole of S

2 mole of Aluminun react with 3 mole of sulfur

2.36 mole of Al react with (2.36 .3)/2 = 3.54 m of S

As I have 2.25 mole of S, and I need 3.54 S, is my limiting reagent so the limiting in excess is the Al.

3 mole of S react with 2 mole of Al

2.25 mole of S react with (2.25 m . 2)/3 = 1.50 mole

I need 1.50 mole of Al and I have 2.36, that's why the Al is in excess.

2.36 mole of Al - 1.50 mole of Al = 0.86 mole

This is the quantity of Al without reaction.

Molar mass . mole = Mass →  26.98 g/m . 0.86 m = 23.2 g

7 0
4 years ago
A chef in restaurant baking 2 different desserts in the oven . He removes a pumpkin and some chocolate chip cookies at the same
valentina_108 [34]

Answer:

the air molecules from the cookies diffused faster than the air molecules from the pumpkin

Explanation:

The smell of cookies reaches first because the air molecules from the cookies were able to diffuse faster than the air molecules from the pumpkin.

<em>At constant temperature, the diffusion rates of two molecules would be dependent on the size of the molecules. The bigger the size of the molecule, the more time it will take for the molecule to diffuse and vice versa. </em>

Thus, <u>since the pumpkin and the cookies were baked at the same temperature, the smell of the cookies was perceived first because the air molecules of the cookies are smaller in size than the air molecules of the pumpkin.</u>

5 0
3 years ago
A stream of methane gas at 25 bar and 100°C flows into a container that contains methane gas initially at 1 bar and 100°C until
Dafna11 [192]

Since Methane is assumed an ideal gas, we need to know its moles in each streams.

Therefore, we can use the ideal gas law to find the mole in the container by:  

P V=nRT         ⇒     n=PV/R T

n=no of moles of the gas = mass/molar mass

Molar mass o f CO2=44g/mol, mass = 44g

P= 25bar = 101000X25Pa=2.5x106Pa

V = 20L = 20dm3 = 0.02m3

T=100C=373K

R=8.314J/mol.K

n1= 2.5x106Pa x 0.02m3 / 8.314J/mol.K x 373K

n1 = 16.1mols

Similarly for stream 2, we have n2 which is

P=1bar = 100000Pa

T= 100C= 373K

V=200L = 0.02m3

n2= 1x105Pa x 0.02m3 / 8.314J/mol.K x 373K

n1 = 0.645mol

So the new stream is an addition of these two streams of methane which has

n3 = n1 + n2 =16.75mols of methane

T=?

V=200L=0.02m3

P = 25Bar = 2.5x106Pa

T= PV/nR

T = 2.5x106Pa x 0.02m3 / 16.75 x 8.314

T=359K

So the final temperature of the gas in the tank is 359K

6 0
3 years ago
The EPA tracks the amount of DDT that has entered into our water systems to ensure water safety. Calculate the ppm for a solutio
Brilliant_brown [7]
I think the answer is C. i’m not sure mate
8 0
3 years ago
Other questions:
  • How many miles of barium hydroxide are in 2400 grams of Ba(OH)2
    8·2 answers
  • Which of the following is most likely the distance between two places on Earth?
    7·2 answers
  • At what height above the earth surface will the gravitational acceleration be 5m
    15·1 answer
  • The atomic symbol Superscript 206 subscript 82 upper P b. represents lead-206 (Pb-206), an isotope that has 82 protons and 124 n
    6·2 answers
  • How many grams are in 3.93 x 10^24 molecules of CCl4?
    9·1 answer
  • Calculate the wavelength (in nm) of the blue light emitted by a mercury lamp with a frequency of 6.32 × 1014 Hz.
    15·1 answer
  • What is the pH of a KOH solution that has [H ] = 1. 87 × 10–13 M? What is the pOH of a KOH solution that has [OH− ] = 5. 81 × 10
    6·1 answer
  • How is star stuff connected to the sun?
    11·1 answer
  • What would be the minimum energy Emin required to excite a hydrogen atom from its lowest energy level
    9·1 answer
  • To study a key fuel-cell reaction, a chemical engineer has 20.0-L tanks of H₂ and of O₂ and wants to use up both tanks to form 2
    7·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!