C
Tarnishing of silver is caused by hydrogen sulfide and other sulfur containing compounds in the air reacting to the silver and resulting in a fine layer of silver sulfide. The other answers don't make sense
Pure Aluminum is too expensive
Answer:
A mutation in Jackie's genes culminated in developing a new enzyme, resulting in the long-distance running phenotype. Jackie appears to have either the A1Am or A2Am gene variants. Jackie used to play for long periods without tiring, suggesting that her gene variants could generate a protein that results in a stamina feature. Jackie's father bears the A1A2 gene. Since Jackie's mother is a good sprinter, I suspect she bears A1A1 gene variants. Sprinters have much ACTN3 protein in their cells, so that she may have two copies of the A1 gene variant. This means Jackie has at least one clone of the A1 gene allele. People with one or two versions of the A1 gene variant, on the other hand, are rarely successful long-distance runners. Out of 100 total distance runners, only 28 (25 and 3) have an A1 gene copy. Since the gene variants she may have inherited from her parents cannot justify her stamina, she may have a mutant gene version that contains a long-distance running protein. However, I do not believe she has AmAm gene versions because mutations are uncommon. Jackie is an elite long-distance runner due to a gene that no one else in her family has.
Answer:
Here's what I get
Explanation:
1. Nickel sulfate
base + acid ⟶ salt + water
NiSO₄ is a salt of the base Ni(OH)₂ and the acid sulfuric acid.
Hydroxides of transition metals are insoluble; most sulfates are soluble.
2. Carbonate + acid
Most carbonates are insoluble.
They react with acids to form carbonic acid (H₂CO₃), which decomposes into water and carbon dioxide.
Answer:
When heat is added to a substance, the molecules and atoms vibrate faster. As atoms vibrate faster, the space between atoms increases. The motion and spacing of the particles determines the state of matter of the substance. The end result of increased molecular motion is that the object expands and takes up more space.
Explanation:
Hope this helps :)