Answer:
Maybe (yes/no)
Explanation:
Cause some theories about the end of the universe. The fate of the universe is determined by its density. The preponderance of evidence to date, based on measurements of the rate of expansion and the mass density, favors a universe that will continue to expand indefinitely, resulting in the "Big Freeze" scenario below.
Answer:
All of the given statements are true.
Explanation:
All the elements are heavier than Bismuth (Bi) are radioactive.
The time for half of the original sample to spontaneous decay is called half life (
)
All radioactive elements are spontaneously decaying towards formation of a stable element.
Radioactive elements undergo decay in order to attain stability.
Radioactivity is a natural part of our environment. The earth also contains several primordial long-lived radioisotopes that have survived to the present in significant amounts.
Hence, all the given statements are true.
Molar mass NaHCO₃ = 23 + 1 + 12 + 16 x 3 = 84 g/mol
1 mole ---------- 84 g
? mole ---------- 110 g
moles NaHCO₃ = 110 . 1 / 84
moles NaHCO₃ = 110 / 84
= 1.309 moles
hope this helps!
Answer:
b) 2.0 mol
Explanation:
Given data:
Number of moles of Ca needed = ?
Number of moles of water present = 4.0 mol
Solution:
Chemical equation:
Ca + 2H₂O → Ca(OH)₂ + H₂
now we will compare the moles of Ca and H₂O .
H₂O : Ca
2 : 1
4.0 : 1/2×4.0 = 2.0 mol
Thus, 2 moles of Ca are needed.
Answer:
The only nonmetal in group 14 is carbon.
Explanation:
