Answer:
A. Elements
Elements are substances that cannot be separated into simpler substances. Salt is made up of the elements sodium and chloride. Water is made up of the elements hydrogen and oxygen, to list a few.
Answer:
0.25 g of U-235 isotope will left .
Formula used :
where,
N = amount of U-235 left after n-half lives = ?
= Initial amount of the U-235 = 1.00 g
n = number of half lives passed = 2
0.25 g of U-235 isotope will left .
Answer:
The mass of 3.491 × 10¹⁹ molecules of Cl₂ of Cl₂ is 4.11 × 10⁻³ grams
Explanation:
The number of particles in one mole of a substance id=s given by the Avogadro's number which is approximately 6.023 × 10²³ particles
Therefore, we have;
One mole of Cl₂ gas, which is a compound, contains 6.023 × 10²³ individual molecules of Cl₂
3.491 × 10¹⁹ molecules of Cl₂ is equivalent to (3.491 × 10¹⁹)/(6.023 × 10²³) = 5.796 × 10⁻⁵ moles of Cl₂
The mass of one mole of Cl₂ = 70.906 g/mol
The mass of 5.796 × 10⁻⁵ moles of Cl₂ = 70.906 × 5.796 × 10^(-5) = 4.11 × 10⁻³ grams
Therefore;
The mass of 3.491 × 10¹⁹ molecules of Cl₂ of Cl₂ = 4.11 × 10⁻³ grams.
The volume that is needed to react completely with 0.100 mol of lead nitrate is 0.400 L. It is because 2 moles of HCl are required for every mole of lead nitrate.
2 x 0.100 mole Pb(NO₃) = 0.200 mole HCl
0.200 mol HCl = L x 0.500 M
