All categories

3 years ago

What is the definition of physical and chemical changes?

2 answers:

6 0

Physical change, a change that occurs physically, and can also be seen physically. But chemically, it's a change that occurs within the chemical, and most likely not be seen within the eyes, but, has a different charater afterward.

BaLLatris [955]3 years ago

3 0

A physical change in a substance doesn't change what the substance is. In a chemical change where there is a chemical reaction, a new substance is formed and energy is either given off or absorbed. For example, if a piece of paper is cut up into small pieces it still is paper.

You might be interested in

Help on this question!

enyata [817]

Answer:

True, The Answer is true. Mechanical digestion involves physically breaking the food into smaller pieces.

6 0

3 years ago

Read 2 more answers

What are the four types of biological molecules and their main function in the human body?

Flauer [41]

Answer:

There are four major classes of biological macromolecules (carbohydrates, lipids, proteins, and nucleic acids)

Explanation:

There are four major classes of biological macromolecules (carbohydrates, lipids, proteins, and nucleic acids), and each is an important component of the cell and performs a wide array of functions. ... Biological macromolecules are organic, meaning that they contain carbon.

7 0

3 years ago

A 25.0 g piece of aluminum (which has a molar heat capacity of 24.03 J/mol°C) is heated to 86.4°C and dropped into a calorimeter

Ira Lisetskai [31]

Answer:

m H2O = 56 g

Explanation:

Q = mCΔT

∴ The heat ceded (-) by the Aluminum part is equal to the heat received (+) by the water:

⇒ - (mCΔT)Al = (mCΔT)H2O

∴ m Al = 25.0 g

∴ Mw Al = 26.981 g/mol

⇒ n Al = (25.0g)×(mol/26.981gAl) = 0.927 mol Al

⇒ Q Al = - (0.927 mol)(24.03 J/mol°C)(26.8 - 86.4)°C

⇒ Q Al = 1327.64 J

∴ mH2O = Q Al / ( C×ΔT) = 1327.64 J / (4.18 J/g.°C)(26.8 - 21.1)°C

⇒ mH2O = 55.722 g ≅ 56 g

5 0

3 years ago

"solid potassium iodide decomposes into iodine gas and solid potassium. Write a a balanced chemical equation for this reaction"

wel

$KI (s) ----\ \textgreater \ K(s) + I_2 (g)$

Now, balance the equation:

$2KI (s) ----\ \textgreater \ 2K(s) + I_2 (g)$

$I_2$ in gaseous state exist as a diatomic molecule.

3 0

3 years ago

A television weights 8.50 pounds. How many grams is this?

kolezko [41]

Answer:

3,855.532 grams

Explanation:

1 pound = 453.592 grams

8.50 = ? grams

--> 8.50 * 453.592 = 3,855.532 grams.

4 0

3 years ago