Answer:
26.56g
Explanation:
The half life of an isotope decay is the time transcurred when the initial amount of the isotope decays to the half of its amount.
For the problem, when 1 half life transcur, the sample has a mass of:
425g / 2 = 212.5g
When 2 half lives transcur:
212.5g / 2 = 106.25g
3 half lives:
106.25/2 = 53.13g
And the amount that is found after 4 half lives is:
53.13/2 =
<h3>26.56g</h3>
Answer:
+1
Explanation:
Na₂O₂
NOTE: the oxidation number of oxygen is always –2 except in peroxides where it is –1.
Thus, we can obtain the oxidation number of sodium (Na) in Na₂O₂ as illustrated below:
Na₂O₂ = 0 (oxidation number of ground state compound is zero)
2Na + 2O = 0
O = –1
2Na + 2(–1) = 0
2Na – 2 = 0
Collect like terms
2Na = 0 + 2
2Na = 2
Divide both side by 2
Na = 2/2
Na = +1
Thus, the oxidation number of sodium (Na) in Na₂O₂ is +1
They move freely and combine with each other.
Answer is: D.The viewer travels through the electron cloud, then the nucleus, and then the electron cloud again.
Atom is composed of the nucleus and the electron cloud.
Protons (positive particles) and neutrons (neutral particles) are in the nucleus of an atom and electrons (negative particles) are in the electron cloud.
Nucleus is in the centar of the atom atom and electron cloud is surrounding it.
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