Answer:
I think it's B
Explanation:
I dont have much experience with the periodic table, but I just think its B.
There are 3.98 × 10^23 atoms of oxygen in the sample.
Given that;
1 mole of Mo(NO3)6 contains 6.02 × 10^23 atoms of Nitrogen
x moles of Mo(NO3)6 contains 2.22 x 10^22 atoms of nitrogen
x = 1 mole × 2.22 x 10^22 atoms/6.02 × 10^23 atoms
x = 0.0368 moles
The number of oxygen atoms in the sample is given by; 0.0368 × 6.02 × 10^23 × 18
Therefore, there are 3.98 × 10^23 atoms of oxygen in the sample.
Learn more: brainly.com/question/9743981
Answer:
Explanation:
alright, dawg, lets get this bread. CHEMISTRY? OH YEAH I LOVE CHEMISTRY.
what is a mol? do you know who avogadro is? sounds like avocado. free shavocado. ok so you MUST REMEMBER THIS NUMBER PLEASE.
please remember this number and commit it to your memory: avogadros number

this is how much a mole is. you know how a pair is 2 and a dozen is 12? ok so a mole is
it is confusing at first but hopefully this helps you to understand.
now that we understand this..... lets perform this calculation with a calculator

notice i divide the question by the avogadros number to find out how many moles are in the number. ok but listen... it gets into a tough area here... because HOW ARE WE TO DIVIDE SUCH A HUMONGOUS NUMBER BY ANOTHER HUMONGOUS NUMBER?!?!?
its easy, its cake, just listen this is how you do it. only focus on the numbers NOT the 10 exponential ones. so just 3.90 and 6.02 ok? lets divide these two numbers 3.90 / 6.02 and we get 0.6478... how interesting... ok now lets deal with the exponents of 10. notice that we are DIVIDING these numbers so think of it as subtracting the exponents of ten..... 22 minus 23 equals -1
so we have 
now this negative 1 thing is annoying so lets just make it to the power of 0

and anything to the power of 0 just becomes 1.
0.06478
so this is our answer but keep in mind we need 3 sig figs. if we round then we get 0.0648
put this into scientific notation we get 
40 watts because 120-80 is forty or 80 + 40 - 120
Answer:
a. similar properties
Explanation:
In a given column of the periodic table, the elements have similar properties.
A column on the periodic table is known as a group or family. The group is a vertical arrangement of elements on the periodic table.
Elements in the same group have the same number of valence electrons after their group number.
For example, all the elements in group 1 have one valence electron. Those in group 2 have 2 valence electrons.
The valence electrons of an atom determines its chemical properties. So, all elements in the same group have the same chemical properties.