Answer:
The periodic table tells you the atomic number (which tells you the number of protons and electrons). It also includes the mass number, which is the sum of the protons and neutrons in the nucleus of an atom.
The molecular mass of sodium = 23g
One mole of sodium consists of 23 g of sodium
One mole consists of 1 Avagadro(6.022 x 10^23 molecules) number of molecules
Therefore 23 g consists of 6.022 x 10^23 molecules of Sodium.
Hence 7.45 x 10^3 g of Sodium will consist of x no of molecules of sodium.
x no of molecules =
(7.45 x 10^3 g/23 g) x (6.022 x 10^23)
=1950.6 x 10^ 23 molecules (atoms).
The primary reason that large numbers of people left Ireland in the 1840s and 1850s was MASS STARVATION.
Great Famine or Great Hunger was a period in Ireland where mass starvation, diseases, and emigration occurred between 1845 to 1852.
The Great Famine was caused by Phytophthora infestans, a disease that infests in potatoes. Though the potato infestation spread throughout Europe, it greatly affected Ireland, where 1/3 of its population was dependent on the potato crop as their primary source of food.
The loss of their primary source of food led to mass starvation, sickness, and eventual death. Others opted to leave Ireland and seek shelter and food in other countries to survive.
If the angle is either 0 or 180, that means that there is either negative or positive work, so A and D are not correct.
If the angle is 45, then there is still some work involved.
The only option where there is no work done by a force is B. when the angle is between the force and displacement is 90.
Answer:
The theory of plate tectonics states that the Earth's solid outer crust, the lithosphere, is separated into plates that move over the asthenosphere, the molten upper portion of the mantle. Oceanic and continental plates come together, spread apart, and interact at boundaries all over the planet.
Explanation:
