The best way (in my opinion) is to put it in a table or spreadsheet.
The heat required to raise the temperature of the cup from 25 c to 50 c is calculated as follows
Q (heat) = c x delta T
c = specific heat capacity = 0. 820 j/c
delta T = change in temperature ( 50 c- 25 c = 25c
= 0.820 j /c x 25 c = 20.5 j
One of the differences I can think of is that hydrogen is no longer listed as a group I element.
According to the mendeleev tables that I looked up, hydrogen is catorgrized as a group I element, along with Lithium, sodium, Potassium etc. However, nowadays, hydrogen does not belong to any groups in the periodic table. This is because there are arguments about whether hydrogen belongs to group I. Group I elements are all alkali metals, while hydrogen is not. However, some people says that hydrogen only have one outer shell electron so it should be in group I. Some people even say hydrogen should belong to group VII because it only needs one more electron in order to achieve the duplet of electrons.
Therefore as you may notice, hydrogen in modern periodic tables are put in the center of the periodic table on the top.
<span>The notation of the isotopes using the atomic number and the mass number consists of the symbol of the atom, preceded by the mass number as a superscript and the atomic number as a superscript.
All the isotopes of the same element have the same atomic number. They only vary the mass number.
So, all the isotopes of oxygen have atomic number 8.
The isotope oxygen-16 has mass number 16, so it is written with the symbol O preceded by the number 16 as a superscript and the number 8 as a subscript (the two numbers to the right of the chemical symbol).
The isotope oxygen-17 has mass number 17, so it is written with the symbol O preceded by the number 17 as a superscript and the number 8 as a subscript.
The isotope oxygen-18 has mass number 18, so it is written with the symbol O preceded by the number 18 as a superscript and the number 8 as a subscript.</span>
