The correct answer is a descriptive investigation.
An investigation which does not involve hypotheses called descriptive investigation.
Hypotheses are termed as scientific hypotheses and require that one can test it. In hypothesis, previous observation can not satisfactorily be explained with an available scientific theory.
Working hypotheses are being proposed for further research.
Answer:
Explanation:
Pair 2.50g of O₂ and 2.50g of N₂
The atoms sample with the largest number of moles since the masses are the same would be the one with lowest molar mass according the the equation below:
Number of moles = 
Atomic mass of O = 16g and N = 14g
Molar mass of O₂ = 16 x 2 = 32gmol⁻¹
Molar mass of N₂ = 14 x 2 = 28gmol⁻¹
Number of moles of O₂ = 
= 0.078mole
Number of moles of N₂ = 
= 0.089mole
We see that N₂ has the largest number of moles
Answer:
A. 28 years
Explanation:
Applying,
R = R'(2ᵃ/ⁿ).............. Equation 1
Where R = Original sample, R' = Sample left after decay, a = Total time taken to decay, n = half life.
From the question,
Given: R = 12 g, R' = 6 g, a = 28 years.
Substitute into equation 1 and solve for n
12 = 6(2²⁸/ⁿ)
12/6 = 2²⁸/ⁿ
2²⁸/ⁿ = 2
Equation the base,
28/n = 1
n = 28 years.
Hence the half-life is 28 years
Answer:
chlorine is a non metal.
sodium is a alkali metal.
helium is a noble gas.
nickel is a transition metal
Some offspring may be tall, some may be short, and some may be medium medium sized.
