1. This is a general physical law derived from empirical observations by what Isaac Newton called inductive reasoning.
2. Kepler's second law of planetary motion describes the speed of a planet traveling in an elliptical orbit around the sun. It states that a line between the sun and the planet sweeps equal areas in equal times. Thus, the speed of the planet increases as it nears the sun and decreases as it recedes from the sun.
3.According to this law the expression P2a−3 has the same value for all the planets in the solar system. Here P is the time taken for a planet to complete an orbit round the sun, and a is the mean value between the maximum and minimum distances between the planet and sun
4. When a planet or moon travels once around an object this is considered a revolution.
5. The lunar phase or phase of the moon is the shape of the illuminated (sunlit) portion of the Moon as seen by an observer on Earth. The lunar phases change cyclically as the Moon orbits the Earth, according to the changing positions of the Moon and Sun relative to the Earth.
Chemical reactions involve breaking chemical bonds between reactant molecules (particles) and forming new bonds between atoms in product particles (molecules). The number of atoms before and after the chemical change is the same but the number of molecules will change
Answer:
0.723 mol
Explanation:
Mole -
Moles is denoted by given mass divided by the molecular mass ,
Hence ,
n = w / m
n = moles ,
w = given mass ,
m = molar mass .
From the information of the question ,
w = 150.0 g
As we known the molar mass of lead is -
m = 207.2 g/mol
Hence , the value for the sample of mole can be calculated by using the above formula ,
n = w / m
putting the respective values ,
n = 150.0 g / 207.2 g/mol = 0.723 mol
Answer:
Examples of element making (nucleogenesis) in helium burning reactions: 3 helium atoms fusing to give a carbon atom: 3 4He → 12C. carbon atom + helium atom fusing to give an oxygen atom: 12C + 4He → 16O.
Explanation: