Answer:
The answer to your question is below
Explanation:
a)
Number of atoms = ?
moles of Fe = 4.75
-Use proportions to solve this problem
1 mol of Fe --------------------- 6.023 x 10²³ atoms
4.75 moles --------------------- x
x = (4.75 x 6.023 x 10²³) / 1
x = 2.86 x 10²⁴ / 1
Number of atoms = 2.86 x 10²⁴
b)
Number of moles = ?
moles of 1.058 moles of H₂O
I think this question is incorrect, maybe you wish to know the number of atoms or grams of H₂O.
c)
Number of atoms = ?
moles of Fe = 0.759
1 mol of Fe ------------------ 6.023 x 10²³ atoms
0.759 moles --------------- x
x = (0.759 x 6.023 x 10²³) / 1
x = 4.57 x 10²³ / 1
Number of atoms of Fe = 4.57 x 10²³ atoms
d)
Number of molecules = ?
moles of H₂O = 3.5 moles
1 mol of H₂O ------------------ 6.023 x 10²³ molecules
3.5 moles ------------------ x
x = (3.5 x 6.023 x 10²³) / 1
x = 2.11 x 10²⁴ molecules
Number of molecules = 2.11 x 10²⁴
<u>Answer:</u>
17%
<u>Explanation:</u>
Mass of a piece of copper calculated by student = 8.3 grams
Actual mass of copper = 10 grams
We know the formula for the percent error:
Percentage error = (| experimental value - actual value | / actual value) * 100
So substituting the given values in the above formula:
Percent error = (|8.3 - 10| / 10) * 100 = (1.7/10) * 100 = 17%
Answer:
hydrogen (H), nitogen (N), oxygen (O), fluorine (F), chlorine (Cl), helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), radon (Rn)
Explanation: found this online, it's best to remember them.
The answer to this is false.
Answer:
Part a:
Isobars: Ca-41, K-41 and Ar-41
Part b:
Number of proton
Part c:
Incorrect statement
Explanation:
Part a:
Nuclei with same mass number are called isobars.
Given:
Ca-40, Ca-41, K-41 and Ar-41
Ca-41, K-41 and Ar-41 have equal mass numbers, so these are isobars.
Part b:
Atomic number of Ca = 20
Atomic no. = Number of proton.
So, Ca-40 ans C-41 have same number of proton or in other words proton count is common in both.
Part c:
Number of neutrons in Ca-41
Atomic number = 20
Mass number = 41
Number of neutron = Mass number -atomic number
= 41 -20 = 21
Number of neutrons in K-41
Atomic number = 19
Mass number = 41
Number of neutron = Mass number -atomic number
= 41 -19 = 22
Number of neutrons in Ar-41
Atomic number = 18
Mass number = 41
Number of neutron = Mass number -atomic number
= 41 -18 = 23
So, the statement is incorrect.
