Answer:
Mass = 13.23 g
Explanation:
Given data:
Mass of oxygen = 48.0 g
Mass of propane burn = ?
Solution:
Chemical equation:
C₃H₈ + 5O₂ → 3CO₂ + 4H₂O
Number of moles of oxygen:
Number of moles = mass/molar mass
Number of moles = 48.0 g/ 32 g/mol
Number of moles = 1.5 mol
now we will compare the moles of propane and oxygen.
O₂ : C₃H₈
5 : 1
1.5 : 1/5×1.5 = 0.3 mol
Mass of propane burn:
Mass = number of moles × molar mass
Mass = 0.3 mol × 44.1 g/mol
Mass = 13.23 g
Answer: See below
Explanation: a. The mass of an element is composed of:
protons: 1 amu each
neutrons: 1 amu each
electrons: 0 amu each
Only the protons and neutrons are counted in the atomic mass of an element
b. Electrons are assigned a mass of 0. They do have a mass, but it is exceedingly small compared to the protons and neutrons, so they are left out of the calculation of an element's mass.
c. An element becomes unstable if the neutrons exceed the protons by a certain ratio, dependent on the element.

The relationship between mass of matter per unit volume is known as :

_____________________________

Answer:
The correct answer is 1 millon years.
Explanation:
Fossil rocks serve to study the evolution of species throughout history. Species usually adapt to survive the changing environment around them. Given this fact, we can deduce that the oldest species were very different from the way they are today. This means that the current species are more similar to those that preceded them more recently. The fossil of 1 million years ago is the most similar to today's horse.
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