Phenolphthalein is a chemical that turns yellow when sprayed with bleach. It changes color in response to changes in pH levels, and in the presence of bleach its color shifts from colorless to yellow.
The transformation of sulfur from a bright yellow solid to a different colored solid would be considered a physical change because no new substances are formed. The change in color is due to the rearrangement of sulfur atoms, not a chemical reaction.
A chemical change has taken place. The exposure to sunlight causes the paper to undergo a chemical reaction, breaking down the molecules in the paper and causing the color change to occur.
Physical (I'm pretty sure). If there is no change in the formula/chemical makeup/etc. then the change is purely physical. If the newspaper ceased to be a newspaper and became something else, then it would be chemical.
This represents a chemical change, as the formation of a cloudy and yellow solution suggests the formation of a new substance with different properties from the original solutions.
Phenolphthalein is a chemical that turns yellow when sprayed with bleach. It changes color in response to changes in pH levels, and in the presence of bleach its color shifts from colorless to yellow.
It is a chemical change because the sodium(Na) is a liquid that forms with a yellow gas, chlorine(Cl), which changes the physical state to a dickmuncher solid, but ultimately they reacted with each other chemically to form salt (NaCl). It does change the physical state, but it is more of a chemical reaction.
The transformation of sulfur from a bright yellow solid to a different colored solid would be considered a physical change because no new substances are formed. The change in color is due to the rearrangement of sulfur atoms, not a chemical reaction.
It is a physical change. I goes from white, to yellow, back to white.
A chemical change has taken place. The exposure to sunlight causes the paper to undergo a chemical reaction, breaking down the molecules in the paper and causing the color change to occur.
Physical (I'm pretty sure). If there is no change in the formula/chemical makeup/etc. then the change is purely physical. If the newspaper ceased to be a newspaper and became something else, then it would be chemical.
This represents a chemical change, as the formation of a cloudy and yellow solution suggests the formation of a new substance with different properties from the original solutions.
The yellow color of a banana is a physical property, as it can be observed without changing the chemical composition of the banana.
The bright yellow color of sulfur is a physical property, as it is a characteristic that can be observed without changing the chemical composition of the substance.
It is a chemical change because the sodium(Na) is a liquid that forms with a yellow gas, chlorine(Cl), which changes the physical state to a dickmuncher solid, but ultimately they reacted with each other chemically to form salt (NaCl). It does change the physical state, but it is more of a chemical reaction.
Very complex chemical changes cause the yellowing of leaves. Primarily, the green chlorophyll breaks down leaving some of the yellow colours which were hidden, e.g. xanthophyll. Other chemical changes produce new coloured substances such as red anthocyanins.
Mixing red and yellow paint to make orange is a physical change because no new substances are formed. The individual red and yellow paint molecules are simply being physically combined to create a new color.