Answer:
The period 4 alkaline-earth metal has the name Calcium. An isotope of this element having 20 neutrons has a mass number of 40.
Explanation:
Looking at the periodic table 4th row for the alkaline-earth metal, we can find Calcium which has an atomic number of 20 (or protons number, or z). The mass number is given by the sum of protons and neutrons. If the number of protons in this case is 20 and the number of neutrons is also 20, the mass number A = 40.
Elements in the same group have D. Same number of valence electrons.
Answer:
a) Pabs = 48960 KPa
b) T = 433.332 °C
Explanation:
∴ d = 1000 Kg/m³
∴ g = 9.8 m/s²
∴ h = 5000 m
∴ P gauge = - 40 KPa * ( 1000 Pa / KPa ) = - 40000 Pa; Pa≡Kg/m*s²
⇒ Pabs = - 40000 Kg/ms² + ( 1000 Kg/m³ * 9.8 m/s² * 5000 m )
⇒ Pabs = 48960000 Pa = 48960 KPa
a) at that height and pressure, we find the temperature at which the water boils by means of an almost-exponential graph which has the following equation:
P(T) = 0.61094 exp ( 17.625*T / ( T + 243.04 ))......P (KPa) ∧ T (°C)....from literature
∴ P = 48960 KPa
⇒ ( 48960 KPa / 0.61094 ) = exp ( 17.625T / (T+ 243.04))
⇒ 80138.803 = exp ( 17.625T / ( T + 243.04))
⇒ Ln ( 80138.803) = 17.625T / ( T + 243.04))
⇒ 11.292 * ( T + 243.04 ) = 17.625T
⇒ 11.292T + 2744.289 = 17.625T
⇒ 2744.289 = 17.625T - 11.292T
⇒ 2744.289 = 6.333T
⇒ T = 433.332 °C
Answer:
B) Symmetrical and nonpolar
Step-by-step explanation:
The formula is H-C≡C-H.
Each C atom has <em>two</em> electron regions, so VSEPR theory predicts a <em>linear molecular geometry</em> (see image below).
The molecule is symmetrical, because the green line divides the molecule into two halves that are mirror images of each other.
The C-H bonds are slightly polar, because C is more electronegative than H (µ ≈ 0.4 D).
The C atoms are partially negative (red), while the H atoms are partially positive (blue).
However, the two C-H bond dipoles point in <em>opposite directions</em>, so they cancel each other. The molecule has <em>no net dipole moment.</em>
Acetylene is nonpolar.
