Answer:
Explanation:
atomic mass
In 1869, Mendeleev published the first periodic table of the elements. In his periodic table, Mendeleev arranged elements in rows by increasing atomic mass. Within a row, elements with lower atomic masses were on the left. Mendeleev started a new row every time the chemical properties of the elements repeated.
Moles of Na2SO4 = conc. x volume(dm3)
= 2 x (2500cm3/1000)
= 5 mol
Mass of Na2SO4 = moles x molar mass
= 5 x ((23 x 2) + 32.1 + (16 x 4))
= 710.5g
The mass of a nickel coin is 5 g.
1 mol of Ni weighs 58 g. 1 mol contains 6.022 x 10²³ atoms of Ni.
therefore in 58 g there are 6.022 x 10²³ atoms of Ni
then in 5 g the number of Ni atoms are - 6.022 x 10²³ /58 x 5 = 5.2 x 10²² Ni atoms
Therefore number of Ni atoms are 5.2 x 10²² atoms in a nickel coin
Answer:
Moving objects contain energy. The faster the object moves, the more energy it has. ... Energy can be converted from one form to another form. Kinetic energy can be distinguished from the various forms of potential energy.
Explanation:
