Objects with more mass have more gravity. Gravity also gets weaker with distance. So, the closer objects are to each other, the stronger their gravitational pull is. Earth's gravity comes from all its mass.
Answer:
The correct statement is option c, that is, particles discharged in the air by volcanoes fall to the ground and enrich the soil.
Explanation:
The eruptions of volcanoes lead to the dispersion of ash over the broader regions surrounding the site of eruption. On the basis of the chemistry of the magma, the ash will be comprising different concentrations of soil nutrients. While the major elements found in the magma are oxygen and silica, the eruptions also lead to the discharging of carbon dioxide, water, hydrogen sulfide, sulfur dioxide, and hydrogen chloride.
In supplementation, the eruptions also discharge bits of rocks like pyroxene, potolivine, amphibole, feldspar that are in turn enriched with magnesium, iron, and potassium. As an outcome, the areas which comprise huge deposits of the volcanic soil are quite fertile.
Answer: 0.87 g of an 8% w/w progesterone gel must be mixed with 1.45 g of a 4% w/w progesterone gel to prepare a 5.5% w/w gel.
Explanation:
According to the dilution law,
where,
= concentration of ist progesterone gel = 8%w/w
= weight of ist progesterone gel = x g
= concentration of another progesterone gel = 4% w/w
= weight of another progesterone gel = 1.45 g
= concentration of resulting progesterone gel = 5.5%w/w
= weight of resulting progesterone gel = (x+1.45) g

Thus 0.87 g of an 8% w/w progesterone gel must be mixed with 1.45 g of a 4% w/w progesterone gel to prepare a 5.5% w/w gel.
D - density: 40 mg/ml
V - volume: 175 ml
m - mass: ??
__________
d = m/V
m = V×d
m = 175×40
m = 7000 mg = 7 g
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