Mgcl2 + na2o nog+2nac what type of chemical reaction is this

 MgCl₂  +Na₂O  →MgO + 2NaCl

the type of reaction above  is double replacement reaction

explanation

Double  replacement  reaction   is type of chemical reaction in which  two compound   react  where  positive  ion (cation)  and negative ion (anion) switch  places forming two new  compounds.

in reaction  above the  new  compounds  formed is MgO  and NaCl as Mg²⁺  and O²⁻ switch their place to form MgO  ,  while   Na⁺  and Cl⁻   switch their place to form NaCl

your parents i think this could be it

in scientific notation, the value of the  speed of light in a vacuum

  will be written as 2.995 * 10^8. when this value is represented in the form of

  a * 10^b, then, a = 2.995 and b = 8.

the value of the speed of light in a vacuum given above can also be rounded up to approximately 300000000. in this case, the scientific notation will be written as 3 *10^8.