Question

1.which one reperesents a chemical change?

-heating water to form steam

-sliced aplles, in contact with air, turning brown

-sugar dissolving in hot coffee

-mixing sugar and cinnamon

-cutting a bar of sodium metal into pieces with knife

2 a subsatnce which can be decomposed in two or more simpler subtances by chemical action is called a(n)

-element

-metal

-compound

-mixture

-solution

Answer 1

1.which one reperesents a chemical change?

-heating water to form steam --> this is physical change, since water remains as H2O

-sliced aplles, in contact with air, turning brown --> this is oxidation, Oxygen is added to molecules os it is chemical change

-sugar dissolving in hot coffee --> this is physical change, solid turns to aqueous

-mixing sugar and cinnamon --> this is physical change, ordered solids will form mixed solids

-cutting a bar of sodium metal into pieces with knife --> this is aphysical change, the sodium metal remains as sodium piee

2 a subsatnce which can be decomposed in two or more simpler subtances by chemical action is called a(n)

-element --> false, elements are the simplest form of substances

-metal --> false, since this can be elmeents as well

-compound --> TRUE! compounds ar emade up of at least 2 elements

-mixture --> False --> this is a physical mixture not chemical

-solution --> False, solution are physcal concepts