The Cretaceous-Tertiary extinction event , the name given to the die off dinosaurs, they all died off about 65.5 million years ago . They died by climate and geological changes .
Answer: four.
Carbon has four valence electrons, so it can achieve a full outer energy level by forming four covalent bonds. When it bonds only with hydrogen, it forms compounds called hydrocarbons. Carbon can form single, double, or triple covalent bonds with other carbon atoms
Answer:
81.5g/mol
Explanation:
Molar mass is the ratio between mass of a substance (In this case, 0.207g) and moles presents in this mass.
To solve this question we must find the moles of the gas in order to obtain the molar mass using:
PV = nRT
PV / RT = n
<em>Where P is pressure = 0.980atm</em>
<em>V is volume in Liters = 0.0725L</em>
<em>R is gas constant = 0.082atmL/molK</em>
<em>T is absolute temperature = 68°C + 273.15 = 341.15K</em>
<em />
0.980atm*0.0725L / 0.082atmL/molK*341.15K = n
2.54x10⁻³ moles = n
Thus, the molar mass of the gas is:
0.207g / 2.54x10⁻³ moles
<h3>81.5g/mol</h3>
The history of balloon flight dates to 1783, when two French brothers, Joseph and Etienne Montgolfier, discovered that filling a bag with hot air would cause it to rise. They demonstrated their principle at Annonay, France, on June 4, 1783, with an unmanned balloon made of linen and pape
