Answer:
Q = 768.47 J
Explanation:
Given that,
Mass of the metal, m = 25 g
Initial temperature, T₁ = 21.0 ºC
Final temperature, T₂ = 80.0 ºC
The specific heat of the metal is 0.521 J/gºC.
We know that the heat released due to the change in temperature is given by :

Hence, 768.47 J of heat energy will be needed.
Physical property- is an aspect of matter that can be observed or measured without touching changing it.
Chemical property- may only be observed by changing the chemical identity of a substance.
The difference would be that for physical property's you dont need to do anything to figure out what they are, but for chemical properties you need to change something to observe them.
Answer: 2.3 moles
Explanation:
Recall that based on Avogadro's law, 1 mole of any substance has 6.02 x 10^23 atoms
So if 1 mole of Aluminum = 6.02 x 10^23 atoms
Then, Z moles = 1.4 x 10^24 atoms
To get the value of Z, we cross multiply:
1 mole x 1.4 x 10^24 atoms = Z x (6.02 x 10^23 atoms)
1.4 x 10^24 atoms = Z x (6.02 x 10^23)
Hence, Z = (1.4 x 10^24 atoms) ➗ (6.02 x 10^23 atoms)
Z =2.3 moles
Thus, there are 2.3 moles in 1.4 x 10^24 atoms of aluminum.
A covalent bond is a bond between 2 non metals, they share electrons. Ionic bonding occurs between a metal and a non-metal, and they transfer electrons.
It's a chemical change beacause elements are combining to make something new! :)