Answer:
An experiment is a research method performed within a completely controlled environment that uses groups of individuals ( subjects), one of which the factors being tested are not spplied on, an independent factor of the hypothesys ( to be tested ), for example the resilience of a group of teenagers) and a dependant factor that is applied to check how it varyes depending on the tested factor ( for example, the most challanging experience of their generation)
The answer is common table salt. Looking at the chemical make up, putting an acid (I think chlorine) and and base (probably sodium) makes water (H20) and salt. So you answer would be salt
Answer:
See explanation
Explanation:
The energy of a photon refers to the energy carried by each photon. The energy of a photon is inversely related to its wavelength.
This simply means that the longer the wavelength of a photon, the lower the energy of the photon.
200nm is longer than 130nm, therefore, 130nm photon has more energy than 200nm photon.
This explains the fact that photons with wavelength 130 nm cause the ejection of 6 s electrons from gold, but photons with wavelength 200 nm do not.
Answer:
9.1 KJ
Explanation:
First we must find the number of moles of HBr involved;
number of moles of HBr= mass of HBr/ molar mass of HBr
But molar mass of HBr= 80.91 g/mol
Given mass of HBr from the question= 20.1g
Hence;
Number of moles of HBr= 20.1 g/80.91g
Number of moles of HBr= 0.25 moles of HBr
If 2 moles of HBr has a heat of formation of 72.80KJ
Then 0.25 moles of HBr will have a heat of formation of 0.25× 72.80/2= 9.1 KJ
Therefore; 20.1 g of HBr will have a heat of formation of 9.1 KJ
Half-life is the time required for a quantity to reduce to half its initial value. <span>If four half-lives have elapsed for calcium-45, then it would be 4x162.7 = 650.8 days have passed. Hope this answers the question. Have a nice day. Feel free to ask more questions.</span>
