C. magnetic forces act at a distance
Explanation:
Since he was able to drag the keys along the table by moving the magnet, it shows that magnetic forces acts a distance.
Magnetism is a property exhibited by a wide range of materials.
Around a bar magnet, there are field forces in which the forces of the magnets are felt.
- Magnetic forces are non- contact forces. They don't need to be together to exert their force.
- This is why magnetic forces act at a distance.
learn more:
Electromagnet brainly.com/question/2191993
#learnwithBrainly
The correct answer for box C is coefficient
amount of CaO that would be produced when 35.5g of CaCO3 decompose on heating (Ca= 40, O = 16, C = 12, H = 1
just put the values to have answer
Answer:
The molarity is 8.52M
Explanation:
molality = moles of solute/kg of solvent = 5.2mol/kg
moles of solute = 5.2mole
mass of solute = moles of solute × MW = 5.2 × 56.106 = 291.8g
mass of solvent = 1kg = 1000g
mass of solution = mass of solute + mass of solvent = 291.8g + 1000g = 1291.8g
Density of KOH = 2120g/L
Volume of solution = mass/density = 1291.8/2120 = 0.61L
Molarity = number of moles of solute/volume of solution = 5.2/0.61 = 8.52M
x + y = 100
0.10x + 0.45 y =25
eliminate
x + y = 100
x + 4.5 y = 250
-3.5 y = -150
y = 42.85
x = 57.15
hope this helps
