Which of the following mixtures could not be separated by filtration? salty water muddy water orange juice with pulp in it dusty air

Option (a) is the correct answer.

Explanation:

Filtration is a technique or process in which solid that is suspended in a liquid is separated from the liquid.

For example, a muddy water can be filtered as particles of mud can be separated from the water.

Particles of salt being ionic in nature completely dissolve in water and it forms a homogeneous solution. Therefore, a mixture of salt water cannot be separated.

Thus, we can conclude that out of the given options salty water is the mixture which cannot be separated by filtration.

it's c. elements are placed in rows based on how may valencies electrons have.

the enthalpy of formation of water is given as -285.8kj/mol, which states that the enthalpy of formation is negative.

negative enthalpy of formation indicates that the heat is released during the reaction process. the heat is released from reaction to the surroundings the enthalpy is expressed with a negative sign with the energy given out in the reaction process.

the formation of water takes place by giving out heat which is -285.8 kj/mol.