The element can also be called gold-197. It has Mass number
is 197, atomic number is 79 and electrons 79, Atoms that have the same number
of protons but different number of neutrons. Isotopes have identical numbers of
protons and electrons.
Answer:
82.59 m/s or 297.324 km/h
Explanation:
From the question,
Applying
V = √[2(P'/ρ)].................. Equation 1 ( From
Where V = Speed of the aircraft, Differential Pressure of the air craft, ρ = Density of air at an altitude of 3000 m.
Given: P' = 3100 N/m², ρ = 0.909 kg/m³
Substitute into equation 1
V = √[2(3100/0.909)]
V = √(2×3410.34)
V = √(6820.68)
V = 82.59 m/s
V = 297.324 km/h
Hence the speed of the aircraft is 82.59 m/s or 297.324 km/h
Potassium (K) is in Group I of the periodic table, and elements in the same column (period) are similar. Sodium (Na), or lithium (Li) are similar.
Answer:
Your strategy here will be to use the molar mass of potassium bromide,
KBr
, as a conversion factor to help you find the mass of three moles of this compound.
So, a compound's molar mass essentially tells you the mass of one mole of said compound. Now, let's assume that you only have a periodic table to work with here.
Potassium bromide is an ionic compound that is made up of potassium cations,
K
+
, and bromide anions,
Br
−
. Essentially, one formula unit of potassium bromide contains a potassium atom and a bromine atom.
Use the periodic table to find the molar masses of these two elements. You will find
For K:
M
M
=
39.0963 g mol
−
1
For Br:
M
M
=
79.904 g mol
−
1
To get the molar mass of one formula unit of potassium bromide, add the molar masses of the two elements
M
M KBr
=
39.0963 g mol
−
1
+
79.904 g mol
−
1
≈
119 g mol
−
So, if one mole of potassium bromide has a mas of
119 g
m it follows that three moles will have a mass of
3
moles KBr
⋅
molar mass of KBr
119 g
1
mole KBr
=
357 g
You should round this off to one sig fig, since that is how many sig figs you have for the number of moles of potassium bromide, but I'll leave it rounded to two sig figs
mass of 3 moles of KBr
=
∣
∣
∣
∣
¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯
a
a
360 g
a
a
∣
∣
−−−−−−−−−
Explanation:
<em>a</em><em>n</em><em>s</em><em>w</em><em>e</em><em>r</em><em>:</em><em> </em><em>3</em><em>6</em><em>0</em><em> </em><em>g</em><em> </em>
