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
mafiozo [28]
3 years ago
10

A 0.4272 g sample of an element contains 2.241 x 10 ^21 atoms . what is the symbol of the element?

Chemistry
1 answer:
grin007 [14]3 years ago
5 0

Answer:

Likely \rm In (indium.)

Explanation:

Number of atoms: N = 2.241 \times 10^{21}.

Dividing, N, the number of atoms by the Avogadro constant, N_A \approx 6.023 \times 10^{23} \; \rm mol^{-1}, would give the number of moles of atoms in this sample:

\begin{aligned} n &= \frac{N}{N_{A}} \\ &\approx \frac{2.241 \times 10^{21}}{6.023 \times 10^{23}\; \rm mol^{-1}} \approx 3.72 \times 10^{-3}\; \rm mol \end{aligned}.

The mass of that many atom is m = 0.4272\; \rm g. Estimate the average mass of one mole of atoms in this sample:

\begin{aligned}M &= \frac{m}{n} \\ &\approx \frac{0.4272\; \rm g}{3.72 \times 10^{-3}\; \rm mol} \approx 114.82\; \rm g \cdot mol^{-1}\end{aligned}.

The average mass of one mole of atoms of an element (114.82\; \rm g \cdot mol^{-1} in this example) is numerically equal to the average atomic mass of that element. Refer to a modern periodic table and look for the element with average atomic mass 114.82. Indium, \rm In, is the closest match.

You might be interested in
A sample of nitrogen gas has the temperature drop from 250.°c to 150.°c at constant pressure. what is the final volume if the in
Leviafan [203]
Charles law gives the relationship between temperature of gas and volume of gas.
It states that for a fixed amount of gas, temperature is directly proportional to volume of gas.
V / T = k
where   V- volume , T - temperature and k - constant 
\frac{V1}{T1} =  \frac{V2}{T2}
parameters for the first instance are on the left side and parameters for the second instance are on the right side of the equation.
T1 = 250 °C + 273 = 523 K
T2 = 150 °C + 273 = 423 K
Substituting the values in the equation,

\frac{310 mL}{523 K} =  \frac{V}{423K}
V = 251 mL
the new volume is 251 mL 
6 0
4 years ago
The alkali metals play virtually the same general chemical role in all their reactions. (b) How is it based on atomic properties
vfiekz [6]

b) It is based on atomic properties as alkali metals requires 7 more electrons to complete their outer orbit. And they try to give those electrons to other elements to obtain noble gas configuration.

Noble gases are the gases which do not react easily with anything. They are also called as Inert gases, and belongs to group 18 of the periodic table.

Alkali metals are the substances which are found in Group I of a periodic table. Mostly the elements which are present are:

  • Lithium (Li)
  • Sodium (Na)
  • Potassium (K)
  • Rubidium (Rb)
  • Cesium (Cs)
  • Francium (Fr)

Properties of alkali metals are:  Soft, shiny reactive metals. They are soft enough to cut with knife. Metals react with water and air quickly and gets tarnish, so pure metals are stored in container by dipping them in oil to prevent oxidation.

To know more about Alkali metals, refer to this link:

brainly.com/question/18153051

#SPJ4

6 0
2 years ago
What element do most acids have in common
Dima020 [189]

Answer:

hydrogen

Explanation:

7 0
3 years ago
Use the following equation to answer the questions below.
sertanlavr [38]

Answer:

Explanation:

Here is ur answer what you wanna do first is calculate the first and second numbers and letters this should be ur answer = -394 + 2 x (-242) - (-75) + 2 x 0 = -803 kJ/mol

4 0
3 years ago
Gold is used for jewelry because it is malleable. This means it can be easily molded into different shapes. What is this an exam
anastassius [24]

Malleablity is a physical property so hence

D. Physical property is the answer

6 0
3 years ago
Other questions:
  • What state of matter has a defined volume and takes the shape of its container?
    6·1 answer
  • Arrange these steps related to climate change in the correct order.
    7·2 answers
  • Which mineral(s) might you be examining if you place some hydrochloric (hcl) acid on a sample and it fizzes?
    11·1 answer
  • Any one of the 6 machines that all machines are made of​
    6·1 answer
  • Speed of Light Math Quiz (20 points)
    5·1 answer
  • A process of beacoming better suited to its environment
    13·2 answers
  • How many grams of NaCl can be dissolved in 100 grams of water at 70°C? What is its concentration? (20 pts.)
    5·2 answers
  • Please help out I am having trouble answering this ?
    10·1 answer
  • • How did your experimental absolute zero value compare to the accepted value?
    15·1 answer
  • What coefficients can be used to balance the following equation
    12·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!