Heat required : 4.8 kJ
<h3>Further explanation
</h3>
The heat to change the phase can be formulated :
Q = mLf (melting/freezing)
Q = mLv (vaporization/condensation)
Lf=latent heat of fusion
Lv=latent heat of vaporization
The heat needed to raise the temperature
Q = m . c . Δt
1. heat to raise temperature from -20 °C to 0 °C
2. phase change(ice to water)
3. heat to raise temperature from 0 °C to 25 °C
Answer:
Number of valence electrons
Explanation:
The given question tells you that a certain piece of wire has a mass = 2.0 g per meter
That means that if you consider a piece of wire that is 1 m in length, its mass will be equal to 2.00 g .
According to question,
Now, you know that
1 m = 100 cm
Mass of 2.00 g of copper will correspond to a wire that is a 100 cm long.
This implies that 0.28 gof copper will correspond to a wire that is
0.28 g * 100 cm / 2.0 g = 14 cm long
Hence, 14 cm of the wire would be needed to provide 0.28 g of copper.
Properties of Copper :
High conductivity and ductility.
Non magnetic.
To know more about Copper here:
brainly.com/question/19761029?referrer=searchResults
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Answer:
Number of proton is 11
Number of neutrons is 12
Number of electrons is 10
Explanation:
For a neutral Na, Sodium atom:
The mass number P+N = 23
Atomic number(E or P) = 11
A charged Na atom that has lost an electron is positively charged and so:
Number of proton = 11 (Still the same)
Number of neutrons = 12
Number of electrons = 11-1=10 (the atom has lost an electron)
If an atom loses electron, it becomes positively charged ie P>E
Answer:9.18 m/s
Explanation:
The average speed for the entire trip is found ......total distance/total time. Remember r*t=d, so divide both sides by t and get r = d/t.
So the cyclist went 800+500+1200 m = 2500 m for total distance.
10t =800 leads to t=80 sec
5t=500 leads to t=100 sec
13t = 1200 leads to t = 92.3 sec
total time is 272.3 sec
Average speed for the entire trip is 2500 / 272.3 = 9.18 m/s
