The pebbles become smooth and even because of erosion. the waves from the sea rub against the pebbles this is erosion. x
Molar mass of sodium chloride is 22.99 g/mol (Na+) + 35.45 g/mol (Cl-) = x g/mol. Then take the mass of sodium chloride sample 5 grams and divide by molar mass to get the number of moles. Take this number and multiply it by Avogadro’s number (6.22*10^23 molecules/mol). You now have the amount of molecules in 5 grams of NaCl.
The type of reaction caused by particle accelerators is called photo-fission reaction
Answer:
D) burning a candle
Explanation
When burning a candle no new substance is form.
We have both physical and chemical change occuring.
Physical part: Melting of the solid wax and evaporation of the liquid forms the physical change.
Chemical part: burning of the wax vapour forms the chemical change.
Explanation:
