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
shusha [124]
3 years ago
15

Use the helium-4 isotope to define atomic number and mass number. Why does knowledge of the atomic number enable us to deduce th

e number of electrons present in an atom?
Chemistry
1 answer:
Zanzabum3 years ago
3 0

<u>Answer:</u> The atomic number of helium atom is 2 and mass number of helium atom is 4.

<u>Explanation:</u>

Atomic number is defined as the number of protons or electrons that are present in a neutral atom.  It is represented by the symbol 'Z'

Atomic number = number of protons = number of electrons

Mass number is defined as the sum of number of protons and neutrons that are present in an atom.  It is represented by the symbol 'A'

Mass number = Number of protons + Number of neutrons

The general representation of an isotope is given as _Z^A\textrm{X}

where,

A = mass number of element

Z = atomic number of element

X = symbol of the element

We are given:

An isotope of helium having formula of _2^4\textrm{He}

where,

Atomic number of helium = 2 = Number of protons = Number of electrons

Mass number of helium = Number of protons + Number of neutrons

4 = 2 + Number of neutrons

Number of neutrons = 4 - 2 = 2

Hence, the atomic number of helium atom is 2 and mass number of helium atom is 4.

You might be interested in
Kinetic energy is the energy of motion.<br><br> a) True<br><br> b) False
FinnZ [79.3K]
The answer is a) true 
8 0
3 years ago
Read 2 more answers
What ions are released when water is mixed with a base?​
ZanzabumX [31]

Answer:

When dissolved in water, acids donate hydrogen ions (H+). Hydrogen ions are hydrogen atoms that have lost an electron and now have just a proton, giving them a positive electrical charge. Bases, on the other hand, mixed with water yield hydroxide ions (OH-).

5 0
2 years ago
What is the specific latent heat of fusion of ice if it takes 863 kJ to convert 4.6 kg of ice into water at 0 C?​
allochka39001 [22]

Answer:

1^{f} =187.7 \frac{J}{kg}

Explanation:

SO in order to calculate the specific latent heat of fusion, you need to remember the formula:

1^{f} =\frac{Q}{m}

Where 1^{f} representes the specific latent heart of fusion.

Q represents the heat energy added, usually represented in kJ

m represents the mass of the object, in kg.

Now that we have our formula we just have to put our values into the formula:

1^{f} =\frac{Q}{m}

1^{f} =\frac{863kJ}{4.6kg}

1^{f} =187.7 \frac{J}{kg}

SO our answer would be 1^{f} =187.7 \frac{J}{kg}

7 0
3 years ago
Which of the following is soluble in water? <br>1-glycerin <br>2-sand<br>3-iron filing<br>4-oil​
sineoko [7]

Answer:

1-glycerin

Explanation:

Hope it helps! :)

4 0
3 years ago
Read 2 more answers
A container of a mixture of 4 gases has a total pressure of 35.7 kPa. Gas A has a partial pressure of 7.8kPa. Gas B has a partia
Maurinko [17]

Answer:

partial pressure of gas D Pd = 15.5 kPa

Explanation:

As per the Dalton's law of partial pressure, in a mixture, pressure exerted by each gas when summed gives the total partial pressure exerted by mixture.

P(Total) = P1+P2+P3.....

Given P(Total) = 35.7 kPa

Partial pressure of gas A Pa = 7.8 kPa

Partial pressure of gas B Pb = 3.7 kPa

Partial pressure of gas C Pc =  8.7 kPa

There, Partial pressure of gas D Pd = P(Total) -(Pa+Pb+Pc)

Pd = 35.7-(7.8+3.7+8.7) = 35.7-20.2 kPa = 15.5 kPa

Therefore, partial pressure of gas D Pd = 15.5 kPa

4 0
3 years ago
Other questions:
  • A food web shows
    6·1 answer
  • One of the emission lines that provides the green color in fireworks, which com s from barium salts, has a wavelength of 505nm.
    5·1 answer
  • Daniel Ost’s acclaim is
    12·1 answer
  • What are the properties of elements related to
    10·1 answer
  • Hydrogen sulfide and concentrated sulfuric acid react to form water and sulfur dioxide as shown in the following reaction:
    13·1 answer
  • A mixture of gases at a total pressure of 95 kPa contains nitrogen, carbon dioxide and oxygen. The partial pressure of carbon di
    5·2 answers
  • A solution of H2SO4(aq) with a molal concentration of 5.74 m has a density of 1.238 g/mL. What is the molar concentration of thi
    15·1 answer
  • Some baking soda and vinegar were weighed separately and the weights added together. The two substances are mixed and a chemical
    10·2 answers
  • Why do scorpions glow on a black light?
    6·2 answers
  • Which atom generally obtains a stable configuration by sharing electrons?
    12·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!