For the first question:
Valuable ore deposits and gem crystals are often associated
with igneous intrusions. So for this question the correct option is option “d”.
An example like the Pegmatite’s, which are a form of igneous intrusions, is
responsible for the creation of variety of gems like topaz and tourmaline.
For the second question:
For this specific question, option “c” seems to be the
correct option. Weathering, deposition, compaction, cementation are the
possible sequence that leads to the formation of sedimentary rocks.
LD50 is defined as the lethal dose 50% which describes the amount of material required to kill 50% of the testing population. It is given in units of mg of chemical per kg of bodyweight of the recipient.
Comparing hydrogen peroxide and acetic acid, we see that peroxide has a lower LD50 of 900 mg/kg, with acetic acid having LD50 = 3310 mg/kg. When comparing LD50 values, the smaller value will be the more toxic compound. What this means is that in this case, a smaller amount of peroxide is required to kill 50% of the testing population compared to acetic acid.
Therefore, 3% hydrogen peroxide is more hazardous to consume.
Answer: false
Explanation:
f this helps typically an element wont have a 2 next to it, to see if something is an element or compound check for the element on the periodic table and see if the structure or name matches the one given to you on the question. for example here it is Co2 on the periodic table it's simply written as Co
co2 or carbon dioxide is a compound not an element, you can even check this on the periodic table
Answer:
The rain falling in New England is 2.29 times more acidic than the one in the American Midwest.
Explanation:
The acidity of a solution depends on the concentration of H⁺ ions ([H⁺]). We can calculate this concentration from the pH using the following expression.
pH = -log ([H⁺])
American Midwest
pH = -log ([H⁺])
5.02 = -log ([H⁺])
[H⁺] = antilog (-5.02) = 9.55 × 10⁻⁶ M
New England
pH = -log ([H⁺])
4.66 = -log ([H⁺])
[H⁺] = antilog (-4.66) = 2.19 × 10⁻⁵ M
The ratio of concentrations is:
The rain falling in New England is 2.29 times more acidic than the one in the American Midwest.
