The alkali metals are first column, alkali earth 2nd, halogens 2nd to last, and noble gases last. Hope it helps!
Answer: b design procedure
Explanation:
design a procedure
To find the number of carbon atoms, we <span>multiply </span>the 3.28x10^24 by the ratio, 3/8. The total number of carbon atoms is 1.23 x 10^24 atoms. The total mass of the sample is each number of atoms divided by avogadro's number and multiplied by the molar mass of each. The total mass is 29.96 grams.
Answer:
wavelength = 0.534×10⁻¹⁶ m
Explanation:
Given data:
Frequency of wave = 5.62 ×10²⁴ Hz
Wavelength = ?
Solution:
Speed of photon = wavelength × frequency
wavelength = speed of photon / frequency
Now we will put the values in formula:
wavelength = 3×10⁸ m/s / 5.62 ×10²⁴ Hz
Hz = s⁻¹
wavelength = 3×10⁸ m/s / 5.62 ×10²⁴ s⁻¹
wavelength = 0.534×10⁻¹⁶ m
Amount of Niobium-91 initially
= 300/91 =3.2967mol
2040 years = 3 ×680 = 3 half-lives
therefore, amount left = 0.4121mol
mass of Niobium-91 remaining = 0.4121 ×91 =37.5g
