Sorry I'm so late, but I just took this test and the answer is white (for people who didn't study well ;) )
"<span>An atom is the smallest unit of matter and an element is a pure substance that is made of identical atoms" is correct. Although atoms can be broken down further now, it still take a whole atom to make an element. </span>
The colors of light emitted from heated atoms had very specific energies.
Answer:
E = 3600 J
Explanation:
Given that,
Voltage, V = 115 V
Power of electric bulb, P = 60 W
We need to find the electric energy used in 1 minute. The electric energy use is given by :

Hence, the electrical energy is 3600 J.
Answer:
The magnitude of the net force F₁₂₀ on the lid when the air inside the cooker has been heated to 120 °C is 
Explanation:
Here we have
Initial temperature of air T₁ = 20 °C = 293.15 K
Final temperature of air T₁ = 120 °C = 393.15 K
Initial pressure P₁ = 1 atm = 101325 Pa
Final pressure P₂ = Required
Area = A
Therefore we have for the pressure cooker, the volume is constant that is does not change
By Chales law
P₁/T₁ = P₂/T₂
P₂ = T₂×P₁/T₁ = 393.15 K× (101325 Pa/293.15 K) = 135,889.22 Pa
∴ P₂ = 135.88922 KPa = 135.9 kPa
Where Force =
we have
Force =
.