N - 15 undergoes beta decay and has a half-life of less than 1 minute.
Answer:

Explanation:
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In this case, when solid calcium carbonate, CaCO3 (s), is decomposed by the action of thermal energy (heat), solid calcium oxide, CaO (s) and carbon dioxide gas, CO2 (g) are yielded via the following reaction:

However, since calcium carbonate is solid as well as calcium oxide and carbon dioxide is given off as a gas, we write:

Which also balanced.
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Answer:
The density of this liquid is 0.320 kg/L
Explanation:
Given:
Volume of the Liquid = 0.820 L
Mass of the liquid = 2.56 kg.
To Find:
The density of the liquid in kg/L
Solution:
Density is the mass occupied by the substance in unit volume. This density is essential determining whether the substance floats or sinks. Greek letter(rho) is used to denote density
The equation of for density is


where m is the mass
v is the volume
On substituting the given values


Answer:
A. The spectrum shows a single electron in the 2p subshell.
Explanation:
Using ideal gas equation,
PV=nRT
P=199 kpa
V=4.67 L
T=30+273K= 303K
n= number of moles of gas
R=8.321 L·kPa·K-1·mol-1
So using ideal gas equation,
n=PV/RT
=199*4.67/8.321*303\
=0.37 mol