Answer:
B. materials change their properties.
Explanation:
In a chemical change, materials often change their properties because a re-arrangement of atoms takes place.
A chemical change is one in which new kind of matter is formed.
It is always accompanied by energy changes.
- Chemical changes are not reversible.
- They lead to the production of new kinds of matter
- It involves mass changes
- Requires considerable amount of energy
The organic compound that is <span>used for stored chemical energy and contains carbon, hydrogen, oxygen, and often phosphorous is called lipid.
Lipids are molecules which consist of fats, waxes, and other things and their function is to store energy, and make up cell membranes.
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Someone please answer this I’m stuck on this one as well
Answer: As the temperature of the thermometer has increased it shows that that the reaction that has taken place was exothermic. In exothermic reactions heat is given out and temperature of the surroundings increases which is indicated by the increase in temperature of the thermometer.
Explanation:
Answer: 14.3%Explanation: In order to find the mass percent of hydrogen in this compound, you must determine how many grams of hydrogen you'd get in 100 g of compound.
In your case, you know that an unknown mass of hydrogen reacts with 0.771 g of carbon to form 0.90 g of hydrocarbon, which is a compound that contains only carbon and hydrogen.
Use the total mass of the hydrocarbon to determine how many grams of hydrogen reacted with the carbon.
Now, if 0.90 g of this compound contain 0.129 g of hydrogen, it follows that 100 g of this compound will contain.
So, if 100 g of this compound contain 14.33 g of hydrogen, it follows that the mass percent of hydrogen is 14.3%
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