Answer:
Explanation:
we know that
ΔH=m C ΔT
where ΔH is the change in enthalpy (j)
m is the mass of the given substance which is water in this case
ΔT IS the change in temperature and c is the specific heat constant
we know that given mass=2.9 g
ΔT=T2-T1 =98.9 °C-23.9°C=75°C
specific heat constant for water is 4.18 j/g°C
therefore ΔH=2.9 g*4.18 j/g°C*75°C
ΔH=909.15 j
Answer:
help with problem 4
Explanation:
4. protons are equal to atomic numbers. neutrons are atomic mass minus atomic number. electrons are equal to protons.
5. I don't know, sorry.
Explanation:
As a neutral lithium atom contains 3 protons and its elemental charge is given as 
. Hence, we will calculate its number of moles as follows.
Moles = 
= 
= 100 mol
According to mole concept, there are 
atoms present in 1 mole. So, in 100 mol we will calculate the number of atoms as follows.
No. of atoms = 
= 
atoms
Since, it is given that charge on 1 atom is as follows.
= 
Therefore, charge present on atoms will be calculated as follows.
Thus, we can conclude that a positive charge of is in 0.7 kg of lithium.
The main use of litmus is to test whether a solution is acidic or basic. Blue litmus paper turns red under acidic conditions and red litmus paper turns blue under basic or alkaline conditions, with the color change occurring over the pH range 4.5–8.3 at 25 °C (77 °F).
Answer:
hydrant flying with balloon, balloon has lithp letting air out, bee: really yum balloon
= = = =
hydrogen helium lithium beryllium
be bore on the balloon, balloon pops, hydrant drops and makes a car bomb
= =
boron carbon
night row general gets hurt by car bomb nearby, that general gets off boat
=
nitrogen
wearing oxygen mask, mask is full of fluride gel, then he got neon teeth
= = =
oxygen fluorine neon
(try making a story out of the elements, use your imagenation)
