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:
B. Aluminum is a good conductor of heat
Explanation:
Physical properties are usually those that can be observed using our senses such as color, luster, freezing point, boiling point, melting point, density, hardness and odor. The Physical Properties of Aluminum are as follows: Color : Silvery-white with a bluish tint.
Answer:
The highly unstable pure sodium or potassium wants to lose an electron and this splits the water atom, producing a negatively charged hydroxide ion and hydrogen and forming an explosive gas that ignites.
Explanation:
Answer: The amount of energy needed to move an electron from one zone to another is a fixed, finite amount. The electron with its extra packet of energy becomes excited, and promptly moves out of its lower energy level and takes up a position in a higher energy level.
Explanation:
Answer:

Explanation:
Hello!
In this case, given the masses of copper, zinc and lead, it is possible to compute the moles via their atomic masses first:

Now, we compute the atomic percentages as shown below:

Best regards!