The Last one thank you thank you hope this helped!
The correct answer is - C. Hydrosphere; geosphere.
The hydrosphere is the sphere which contains all the waters on the planet Earth. The geosphere is the sphere that contains the solid rocky part of the Earth. When the water goes through the porous sediments and enters deeper into the ground, that means the we have an interaction of water and rocks. In other words, since the water is part of the hydrosphere, and the rocks are part of the geosphere, we have an interaction between the hydrosphere and the geosphere.
Answer:
2.5
Explanation:
The given costs for the purchase and delivery of the cupcakes are;
The cost of 10 cupcakes and the delivery fee = $30
The cost of 25 cupcakes and the delivery fee = $67.50
Let 'c' represent the fixed cost of delivery of the cup cakes, and let 'x' represent the cost of each cup cake, we have;
30 = 10·x + c...(1)
67.50 = 25·x + c...(2)
Subtracting equation (1) from equation (2) gives;
67.50 - 30 = 37.50 = 25·x - 10·x + c - c = 15·x
∴ x = 37.50/15 = 2.5
The cost of each cupcake, x = 2.5
(∴ The delivery fee = 30 - 10 × 2.5 = 5)
The cost of each cupcake is 2.5.
Answer:

Explanation:
They gave us the masses of two reactants and asked us to determine the mass of the product.
This looks like a limiting reactant problem.
1. Assemble the information
We will need a chemical equation with masses and molar masses, so, let's gather all the information in one place.
Mᵣ: 239.27 32.00 207.2
2PbS + 3O₂ ⟶ 2Pb + 2SO₃
m/g: 2.54 1.88
2. Calculate the moles of each reactant

3. Calculate the moles of Pb from each reactant

4. Calculate the mass of Pb
