Answer: Electrons
Explanation:The electron itself is small but it takes space as much as an atom by circling around the nucleus.
Answer:
3000 kJ/kg
Explanation:
The calorific value of a substance is the amount of heat produced per unit mass by the combustion of the substance.
It is given by:

where
Q is the amount of heat released
m is the mass of the fuel
In this problem, we have:
m = 60 kg is the mass of fuel
is the amount of heat released
Therefore, the calorific value of the fuel is:

The production of new skin cells is example of regeneration.
Regeneration is process of replacing or restoring not just skin cells, but also other cells in the human organism.
Skin regeneration is replacement of damaged tissue with new tissue.
There are two ways of skin regeneration:
1) reconstruction is a process of rebuilding of damaged skin cells
2) restoration is process of replacing broken cell skins
Epidermal stem cells are those who produces new daughter cell skins.
Epidermal stem cells are in the lowest layer of the skin.
More about skin: brainly.com/question/306377
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Answer: Between 1 and 2.
Explanation:
Half life is the amount of time taken by a radioactive material to decay to half of its original value.
............(1)
where,
a = amount of reactant left after n-half lives = 40
= Initial amount of the reactant = 100
n = number of half lives
Putting in the values we get:

taking log on both sides


Thus half-lives that have elapsed is between 1 and 2