D atoms that are in only one of the reactions and only one of the products should be down first
Answer:
6.02 × 10²³ atoms.
Explanation:
According to the Avogadro number, the one mole of any substance have 6.02 × 10²³ atoms.
The number 6.02 × 10²³ is called Avogadro number. it is the number of atoms, ions or molecules in one gram atoms of element, one gram ions of substance or one gram molecules of a compound.
For one mole of magnesium.
24.305 g of Mg = 1 mole of magnesium = 6.02 × 10²³ atoms of magnesium.
Other example includes:
18 g of water = one mole of water = 6.02 × 10²³ molecules of water.
23 g of sodium = one mole of sodium = 6.02 × 10²³ atoms of sodium.
1) <span> 2.7 g water + 6,6 g carbon dioxide </span>→<span> 9.3 g carbonic acid.
According to </span><span>principle of mass conservation mass of reactants and products are the same after chemical reactio. 2,7 g + 6,6 g = 9,3 g.
2) </span><span>32.0 g sodium hydroxide + 16.0 g hydrofluoric acid --> 14,4 g water + 33.6 g sodium fluoride.
m(water) = 32 g + 16 g - 33,6 g.
3) </span><span>0.60 g calcium carbonate + 0.48 g sodium hydroxide --> 0,63 g sodium carbonate + 0.45 g calcium.
m(sodium carbonate) = 0,6 g + 0,48 g - 0,45 g.
4) </span><span>0.53 g sodium hydroxide + 0.37 g carbon dioxide --> 0,9 g sodium hydrogen carbonate.
m(sodium hydrogen carbonate) = 0,53 g + 0,37 g = 0,9 g.</span>
Option c. dendrochronology
tree rings or dendrochronology they allow to use it in calibration for carbon-14 on temporal placements of fragments of wood (from long dead trees).
Example Bristle cone pines (1957) 4723 years old
B because isotopes have the same number of protons but a different number of neutrons
