The unit expressed in 660 nm of light represents the wavelength of light. If you want to determine the frequency, you use the speed of light to relate the two. The formula is:
c = λν
where
λ is the wavelength
ν is the frequency
c is the speed of light = 3×10⁸ m
Apply SI units:
(3×10⁸ m) = (660×10⁻⁹ m)(ν)
Solving for ν,
<em>ν = 4.55×10¹⁴ s⁻¹</em>
Answer:
Among the different types of scientific knowledge hypotheses are likely to be modified or discarded most frequently. Long ago in the 1600's scientists discarded the phlogiston theory because the new evidence didnt support it.
Explanation:
Hypothesis is the assumption of something possible or impossible to draw a consequence and is provisionally established as the basis for an investigation and which can confirm or deny its validity. For this reason, within scientific research, hypotheses are so important and so changeable that they are modified or discarded more frequently within scientific knowledge.
Based on a work by Johann Joachim Becher, the German scientist Georg Ernst Stahl created the phlogiston theory that said combustion occurred with certain materials because they had an “element” or a common flammable principle that was released at the time of burning . This theory was abandoned because there was no evidence, even through scientific experiments, to prove that this theory is true.
<em>m Na₂CO₃: 23g×2 + 12g + 16g×3 = 106 g/mol</em>
------------------------------
1 mol ------- 106g
X ------------ 10,6g
X = 10,6/106
<u>X = 0,1 mol Na₂CO₃</u>
An anchoring phenomenon anchors all of the learning within a unit. So, it is a unit level event that the classroom is trying to make sense of as they engage in a series of lessons.
Since the questions the students ask about the anchor drive the learning within the unit, the anchor should be complex and require an understanding of several big science ideas to explain.
At strategic moments, the class revisits the anchoring phenomenon to review their initial questions to see which they have answered, which they are making progress on, and what new questions they may have to help us continue learning about the phenomenon.
Throughout the unit, the classroom and each student should be given opportunities to share their thinking and how it relates to the anchoring phenomenon.
YOU SHOULD PUT IT IN YOUR OWN WORDS THOUGH <3
Explanation:
Atomic Number = Number of protons
Mass Number = Number of protons + Number of neutrons
Isotopes are simply atoms of an element with the same number of protons and different number of neutrons.
First Isotope -- 238U
Number of neutrons = Mass Number - Atomic Number
Number of neutrons = 238 - 92 = 146
Second Isotope -- 235U
Number of neutrons = Mass Number - Atomic Number
Number of neutrons = 235 - 92 = 143
