Answer:
69.4
Explanation:
There isn't one, I just took the test.
The answer is b hope it helps u good luck
Answer:
Gold is a relatively dense metal because its atoms have more
protons than atoms of many other metals.
Explanation:
Answer:
ΔE negative,ΔE positive,ΔE positive
Explanation:
Internal energy change of a system is positive when the system acquires energy from outside and internal energy change is negative when energy is being liberated from the system.
a Sweat evaporates from skin,cooling the skin ΔE is negative as heat energy is liberated through evaporation of sweat.
b A balloon expand against an external pressure ΔE positive because external energy is required to expand the balloon.
c An aqueous chemical reaction mixture is warmed with an external flame ΔE is positive because heat energy is provided by the external flame to warm the aqueous chemical reaction.
The mass of an element listed in the Periodic Table is the weighted average of all its naturally occurring isotopes.
Naturally occurring carbon is about
99 % carbon-12 (12.000 u) + 1 % carbon-13 (13.003 u).
That extra carbon-13 makes the <em>average atomic mass</em> greater than 12.000 u.
