False. A physical change does not create a new substance.
Answer: acetic acid structure
Explanation:
In the lewis structure we have 24 valence electrons
The statement which is true is
metals lose electrons to become cations
<u><em>Explanation</em></u>
- metals tends to loss electrons to attain noble gas electrons configuration.
- When metal loses electrons they form a positive charged ions.
- The positively charged ion is known as cations.
- for example sodium metal (Na) loses 1 electron to form a cation with a charge of positive 1 ( Na^+)
B. The unknown solution had the lower concentration.
Explanation:
Osmosis is a phenomenon in which the molecules of the solvent has a tendency to move through a membrane which is semipermeable from lower concentrated side to the higher concentration side, so that the concentrations on both sides of the membrane must be equal.
So the unknown solution may have lesser concentration than the isotonic solution so that molecules of that solution move from less concentrated side to the more concentrated side, so its level drops.
Answer:
The type of allergy test is scratch test.
Explanation:
In a scratch test also called a skin pri c k test or puncture test, an allergy provoking substance placed on the skin is gradually scratched into the skin surface with the aid of a needle or lancet so as to detect bodily reactions to allergens. Some of the types allergens whose reactions are generally tested for include pollen, dust mites, molds and foods.
The scratch test takes about 5 to 10 minutes and it could cause slight pain and the may result in itching feeling at the location where the allergen was introduced.