Answer:
<em>2.085 x 10^-20 J</em>
<em></em>
Explanation:
minimum energy required to produce photoelectric effect in chromium is given as hf = 7.21 x 10^-19 J
The work function of chromium Ф = 4.37 eV = 7.00151 x 10^-19 J
The minimum energy required to eject an electron from from a chromium metal E = ?
From E = hf - Ф
substituting values, we have
E = (7.21 x 10^-19) - (7.00151 x 10^-19)
E = <em>2.085 x 10^-20 J</em>
Answer:
Helium is in group 18 of the periodic table. How is helium different from the other elements in this group? = Helium atoms have 2 valence electrons, while atoms of the other elements in the group all have 8 valence electrons.
An emission spectrum will occur when = An electron releases energy and falls back to a lower energy level.
Explanation:
Answer:
The answers to your questions are given below.
Explanation:
__ NaBr + CaF₂ —> __ NaF + CaBr₂
The above equation can be balance as follow:
NaBr + CaF₂ —> NaF + CaBr₂
There are 2 atoms of F on the left side and 1 atom on the right side. It can be balance by writing 2 before NaF as shown below:
NaBr + CaF₂ —> 2NaF + CaBr₂
There are 2 atoms of Na on the right side and 1 atom on the left side. It can be balance by writing 2 before NaBr as shown below:
2NaBr + CaF₂ —> 2NaF + CaBr₂
Now, the equation is balanced.
Atom >>>> Reactant >>>> Product
Na >>>>>> 2 >>>>>>>>>>> 2
Br >>>>>>> 2 >>>>>>>>>>> 2
Ca >>>>>> 1 >>>>>>>>>>>> 1
F >>>>>>> 2 >>>>>>>>>>>> 2
Answer:
A
Explanation:
it is because it began a new millennium
Conduction-
putting an icepack on injury
grabbing a warm coffee mug
burning yourself by touching boiling water
the handle of a pot being to hot to touch
Convection-
heat from a fire to warm hands
warm water rising to the surface of of the ocean etc.
warm air rising off pavement
an oven that cooks by cycling warm air through the bottom and out the top
Radiation-
cooking popcorn using microwave
heat from the sun hitting a solar panel
( i havent done science in a while cuz im homeschooled but i think most of these are correct)
good luck on what your working on !!
