No one is 100% sure when particles of matter originated however scientist believe it had to be some time before the Big Bang
Answer is: the average atomic mass 217.606 amu.
Ar₁= 203.973 amu; the average atomic mass of isotope.
Ar₂ = 205.9745 amu.
Ar₃ = 206.9745 amu.
Ar₄ = 207.9766 amu.
ω₁ = 1.40% = 0.014; mass percentage of isotope.
ω₂ = 24.10% = 0.241.
ω₃ = 22.10% = 0.221.
ω₄ = 57.40% = 0.574.
Ar = Ar₁ · ω₁+ Ar₂ · ω₂ + Ar₃ · ω₃ + Ar₄ · ω₄.
Ar = 203.973 amu · 0.014 + 205.9745 amu · 0.241 + 206.9745 amu · 0.221 + 207.9766 amu · 0.574.
Ar = 2.855 amu + 49.632 amu + 45.741 amu + 119.378 amu.
Ar = 217.606 amu.
But abundance of isotopes is greater than 100%.
It should be lead, with the fourth isotope weighs 207.9766 amu and an abundance of 52.40.
For a candle to burn, it requires a spark, which provides the activation energy for the oxidation reaction of the hydrocarbon making the candle.
It also requires oxygen to facilitate the oxidation of the hydrocarbon.
Therefore the two main requirements of combustion of a candle are oxygen and a spark (or an initial flame)
Answer:
Scientists seek to eliminate all forms of bias from their research. However, all scientists also make assumptions of a non-empirical nature about topics such as causality, determinism and reductionism when conducting research. Here, we argue that since these 'philosophical biases' cannot be avoided, they need to be debated critically by scientists and philosophers of science.
Explanation:
Scientists are keen to avoid bias of any kind because they threaten scientific ideals such as objectivity, transparency and rationality. The scientific community has made substantial efforts to detect, explicate and critically examine different types of biases (Sackett, 1979; Ioannidis, 2005; Ioannidis, 2018; Macleod et al., 2015). One example of this is the catalogue of all the biases that affect medical evidence compiled by the Centre for Evidence Based Medicine at Oxford University (catalogueofbias.org). Such awareness is commonly seen as a crucial step towards making science objective, transparent and free from bias.
I don't know but I would pick b.2.covalent bonds