Answer:
The hypothesis that eukaryotic cells evolved from a symbiotic association of prokaryotes—endosymbiosis—is particularly well supported by studies of mitochondria and chloroplasts, which are thought to have evolved from bacteria living in large cells.
Explanation: Both mitochondria and chloroplasts are similar to bacteria in size, and like bacteria, they reproduce by dividing in two. Most important, both mitochondria and chloroplasts contain their own DNA, which encodes some of their components. The mitochondrial and chloroplast DNAs are replicated each time the organelle divides, and the genes they encode are transcribed within the organelle and translated on organelle ribosomes. Mitochondria and chloroplasts thus contain their own genetic systems, which are distinct from the nuclear genome of the cell. Furthermore, the ribosomes and ribosomal RNAs of these organelles are more closely related to those of bacteria than to those encoded by the nuclear genomes of eukaryotes.
Answer:
116.88 g
Explanation:
Step 1: Write the balanced equation for the synthesis of NaCl
Na + 1/2 Cl₂ ⇒ NaCl
Step 2: Calculate the moles corresponding to 45.978 g of Na
The molar mass of Na is 22.990 g/mol.
45.978 g × 1 mol/22.990 g = 1.9999 mol
Step 3: Calculate the number of moles of NaCl formed from 1.9999 moles of Na
The molar ratio of Na to NaCl is 1:1. The moles of NaCl formed are 1/1 × 1.9999 mol = 1.9999 mol.
Step 4: Calculate the mass corresponding to 1.9999 moles of NaCl
The molar mass of NaCl is 58.443 g/mol.
1.9999 mol × 58.443 g/mol = 116.88 g
Note that the density of pure aluminum is 2.7 g/cm³ (from tables).
Given:
m = 39.0 g, the mass of the metal
V = 10.0 cm³, the density of the metal
By definition, the density of the metal is
density = mass/volume
= (39.0 g)/(10.0 cm³)
= 3.9 g/cm³
Answer:
The calculated density is not equal to 2.7 g/cm³, therefore the metal sphere is not made of pure aluminum.
The answer would be B) Lower, because pure water freezes at 32 degrees Fahrenheit whereas salt water freezes at 28.4 degrees Fahrenheit. Hopefully this helps!
<span>The rate of crystallizing is equivalent to the rate of dissolving.</span>
