Answer:
Explanation:
To calculate their average atomic masses which is otherwise known as the relative atomic mass, we simply multiply the given abundances of the atoms and the given atomic masses.
The abundace is the proportion or percentage or fraction by which each of the isotopes of an element occurs in nature.
This can be expressed below:
RAM = Σmₙαₙ
where mₙ is the mass of isotope n
αₙ is the abundance of isotope n
for this problem:
RAM of Li = m₆α₆ + m₇α₇
m₆ is mass of isotope Li-6
α₆ is the abundance of isotope Li-6
m₇ is mass of isotope Li-7
α₇ is the abundance of isotope Li-7
Answer: If the potential energy of the reaction system decreases, then kinetic energy in the surroundings increases and the temperature of the surroundings rises
Explanation:
Answer:
The data are inadequate.
Explanation:
In the given question, there are fifteen players on the team.
But Diana and Kinsey survey only the five players on the starting lineup about their favorite mascot.
Based on only a few players out of the total number of players, both Diana and Kinsey can't choose a mascot for the basketball team.
So, the data are inadequate.
Answer:
1. NaOH + H₂O → Na⁺ + OH⁻ + H₂O + heat
2. NaOH + HCl → NaCl + H₂O
Explanation:
1. The dissolving of NaOH in water is an exothermic reaction resulting a heat. It also causes the dissociation of NaOH to its ions (Na⁺ and OH⁻).
So, the balanced equation will be NaOH + H₂O → Na⁺ + OH⁻ + H₂O + heat.
2. The reaction between acid and base resulting salt and water. It is considered as a neutralization reaction.
The reaction between HCl and NaOH will give sodium chloride and water and the balanced equation will be NaOH + HCl → NaCl + H₂O.
Answer:
Explanation:
1 mol of Pb(MnO₄)₂contains 1 mol of Pb atoms.
1. Moles of Pb
2. Atoms of Pb