Answer:
The gas was N₂
Explanation:
V = 3.6L
P = 2.0 atm
T = 24.0°C = 297K
R = 0.0821 L.atm/K.mol
m = 8.3g
M = molar mass = ?
Using ideal gas equation;
PV = nRT
n = no. Of moles = mass / molar mass
n = m/M
PV = m/M * RT
M = mRT / PV
M = (8.3*0.0821*297) / (2.0*3.6)
M = 28.10
Since X is a diatomic molecule
M = 28.10 / 2 = 14.05 g/mol
M = Nitrogen
X = N₂
Answer:- Mass of the titanium alloy is 7.01 g, choice C is correct.
Solution:- The heat of fusion is given as 422.5 joules per gram and it also says that 2960 joules of heat is required to melt the metal completely.
The suggested equation is, 
where Q is the heat energy, m is the mass and Hf is the heat of fusion.
Since, we are asked to calculate the mass, the equation could be written as:

Let's plug in the values in it:

m = 7.01 g
So, the mass of the titanium alloy is 7.01 g, choice C is correct.
Explanation:
Let us assume that volumes is equal to spheres volume of nucleus.
fm = femto meter =
pm = pico meter =
Hence, calculate the volume as follows.
V =
=
= 82.4481
(cubic femtometers)
or, = 82
Now, we will calculate the volume of the atom as follows.
V =
=
= 1436758.4
(cubic picometers)
thus, we can conclude that volume of the nucleus is 82
and volume of the atom is 1436758.4
.
Answer:- 
Explanations:- The first reaction is combustion reaction as the hydrocarbon is burned in presence of oxygen to give carbon dioxide and water.
Second reaction is the synthesis reaction as in general a synthesis reaction looks like:

Third reaction is the decomposition reaction as it looks opposite of synthesis reaction.

In general, a single displacement reaction looks like:

Fourth reaction is single replacement reaction as bromine is replaced by chlorine.
So, the correct choice is the last reaction,
.
Answer:
boron
Explanation:
boron has 5 protons and carbon has 6, so if carbon lost a proton, it would become boron since each element has a unique number of protons.