Answer:
3.51× 10²³ formula units
Explanation:
Given data:
Mass of CaO = 32.7 g
Number of formula units = ?
Solution:
First of all we will calculate the number of moles.
Number of moles = mass/molar mass
Number of moles = 32.7 g/ 56.1 g/mol
Number of moles = 0.583 mol
Number of formula units:
1 mole = 6.022 × 10²³ formula units
0.583 mol × 6.022 × 10²³ formula units / 1 mol
3.51× 10²³ formula units
The number 6.022 × 10²³ is called Avogadro number.
Answer:
A. Protons are positive and carry a charge of +1
B. Neutrons are neutral so carry a charge of 0
C. Electrons are negative and carry a charge of -1
Answer:
About 25 kPa
Explanation:
Pressure decreases with height above sea level.
The calculation is rather complicated, so I will refer to the figure below.
It shows that the pressure at 10 km is about 25 kPa.
Answer:
A. LST
Explanation:
• 1st Law: The path of each planet around the Sun is an ellipse with the Sun at one focus.
• 2nd Law: The line from the Sun to any planet sweeps out equal areas of space in equal time intervals.
• 3rd Law: The square of the orbital period of a planet is directly proportional to the cube of the average distance