Which definition is correct? a physical change creates a new substance because bonds are broken or formed a chemical change occurs when the substance remains the same but the shape, or other physical characteristics change a physical change can happen without changing any characteristics of the substance a chemical change produces a new substance by breaking and forming new bonds

A physical change can happen without changing any of the characteristics, for example if you have an ice cube which is frozen H2O and you let it sit it will melt only changing the physical appearance and the molecules in the substance. A physical change doesn't change the physical composition.

Option (d) is the correct answer.

Explanation:

A physical change is defined as a change which does not cause any change in chemical composition of a substance.

For example, change in shape, size, mass, volume etc are all characteristics of physical change.

Whereas a change that causes change in chemical composition of a substance is known as chemical change.

For example,

A new substance is always formed in a chemical change.

Thus, we can conclude that the definition  a chemical change produces a new substance by breaking and forming new bonds, is correct.

so here we go

atomic mass

239 + 1 = y + 134 + 3 combine like terms

240 = y + 137             subtract 137 from both terms

240 - 137 = y

103 = y

atomic number

94 = z +54 + 0

94 = z + 54               subtract 54 from both sides.

40 = z

answer