Answer : The correct option is, (A) the copper must have combined with another substance.
Explanation :
According to the question, when a sample of copper powder is heated in an evaporating dish by using Bunsen burner then the mass of the powder in the evaporating dish increases after heating that means the copper powder will be combined with the another substance.
If the mass of powder in the evaporating dish is decreases after the heating then the copper powder must have lost some matter.
The given option C and D are wrong statements because the hot copper is less dense than the cold copper and as we know that the density is directly proportional to the mass of a substance that means the hot copper weighs less than cold copper.
Hence, the correct option is, (A) the copper must have combined with another substance.
Answer:
Atomic models are important because, they help us visualize the interior of atoms and molecules, and thereby predicting properties of matter.
Explanation:
We study the various atomic models in our course of study because, it is important for us to know, how did people come to the present concept of an atom. How did physics evolve from classical to quantum physics.
All these are important for us to know and thus, knowledge about various atomic models, their discoveries and drawbacks and finally improvements based on scientific evidence present at that time is important for us to understand the underlying theory very well.
Answer is: atoms have the greatest kinetic energy in <span>liquid iron (2,000°C).
</span>The average kinetic energy of molecules depends on the temperature.
At high temperature(2,000°C), molecules of iron have greater kinetic energy than molecules of iron at low temperature (1,600°C, 65°C and 25°C)..
Answer:
<h2>
</h2>
Explanation:
According to hooks law "provide the elastic limit of an elastic material is not exceeded the extension e is directly proportional to the applied force F"
where F= applied force
k= spring constant
e= extension
Given data
length of string l = 16cm
extension e = 20-16= 4cm
applied force = 5N
we need t o first calculate the spring constant k
apply the formula
we can now calculate the extension of the string when supporting a 6N weight
The length of the string when supporting a 6N weight is
<em>COMMENT </em><em>:According to the analysis an extra weight of 1N will cause add 0.8cm to the length of the string</em>
Answer:
V2 = 57.67cm3
Explanation:
From the question
P1= 30.8, V1=205cm3, T1= 22+273=295K, P2=101.325kPa, T2= 273K, V2= ?
Applying
P1V1/T1= P2V2/T2
Substitute and simplify
(30.8*205)/295 = (101.325*V2)/273
V2= 57.67cm3