Answer:
Q = 5267J
Explanation:
Specific heat capacity of copper (S) = 0.377 J/g·°C.
Q = MSΔT
ΔT = T2 - T1
ΔT=49.8 - 22.3 = 27.5C
Q = change in energy = ?
M = mass of substance =508g
Q = (508g) * (0.377 J/g·°C) * (27.5C)
Q= 5266.69J
Approximately, Q = 5267J
Via half-life equation we have:
Where the initial amount is 50 grams, half-life is 4 minutes, and time elapsed is 12 minutes. By plugging those values in we get:
There is 6.25 grams left of Ra-229 after 12 minutes.
Answer: 
Explanation:
The density 
of a material is given by:
(1)
Where:
is the mass of the cube
is the volume of the cube
Now, the volume of a cube is equal to the length 
of its edge to the power of 3:
(2)
If we know 
, the volume of this cube is:
(3)
Substituting (3) in (1):
(4)
This is the density of the cube
The same braking force does work on these objects to slow them down. The work done is equal to their change in kinetic energy:
FΔx = 0.5mv²
F = force, Δx = distance traveled, m = mass, v = speed
Isolate Δx:
Δx = 0.5mv²/F
Calculate Δx for each object.
Object 1: m = 4.0kg, v = 2.0m/s
Δx = 0.5(4.0)(2.0)²/F = 8/F
Object 2: m = 1.0kg, v = 4.0m/s
Δx = 0.5(1.0)(4.0)²/F = 8/F
The two objects travel the same distance before stopping.
Answer:
your question is incomplete as the options are not given. I guess following is the complete question.
Which of these atoms is most likely to share electrons with other atoms?
a) chlorine (7 valence electrons)
b) calcium (2 valence electrons)
c) argon (8 valence electrons)
d) carbon (4 valence electrons)
e) potassium (1 valence electron)
The correct option is d) carbon (4 valence electrons)
Explanation:
Carbon has four electrons in its valence shell. In order to complete the 8 electrons in its valence shell carbon has to make four covalent bonds by sharing its four electrons with the other atom. Carbon atom will neither gain the electrons nor it losses the electrons to follow the octet rule. So in the above mentioned options carbon is the atom that will share maximum electrons.
→ Chlorine has 7 electrons, it will gain 1 electron. It will not do the sharing.
→ Calcium has 2 electrons, it will lost these 2 electrons to complete its shell.
→ Argon has already a completed shell. It will not react with other atom.
→ Potassium has only 1 valence electron which it will lose to complete its shell.
