Answer:
Group 2A (or IIA) of the periodic table are the alkaline earth metals: beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), and radium (Ra). They are harder and less reactive than the alkali metals of Group 1A.
Explanation:
If an element contains 8 electrons, then there would be 6 electrons that will be placed in the 2nd valence shell. Each shell in an atom can only take up a fixed number of electrons. For the first shell, only two electrons can be found. For the second shell, it can hold up to 8 electrons. However, for this case only six electrons can be found since the others are found in the first shell.
Answer:
Initial volume of the container (V1) = 1.27 L (Approx)
Explanation:
Given:
Number of mol (n1) = 5.67 x 10⁻²
Number of mol (n2) = (5.67 +2.95) x 10⁻² = 8.62 x 10⁻²
New volume (V2) = 1.93 L
Find:
Initial volume of the container (V1)
Computation:
Using Avogadro's law
V1 / n1 = V2 / n2
V1 / 5.67 x 10⁻² = 1.93 / 8.62 x 10⁻²
V1 = 10.9431 / 8.62
Initial volume of the container (V1) = 1.2695
Initial volume of the container (V1) = 1.27 L (Approx)
Answer:
C. Gas exchange occurs through the placenta.
Explanation:
The fetus is a developing baby in the womb or uterus. The fetus is incapable of performing certain life processes itself and hence, depends on the mother to do them. One of these processes is GAS EXCHANGE. Gas exchange occurs in the fetus via a structure called PLACENTA.
Placenta is a structure that forms in the uterus during pregnancy. It helps the developing fetus supply oxygen and nutrients from the mother and also remove wastes from the fetus back to the mother. The oxygen is taken into the fetus via the PLACENTA while the carbon dioxide (waste product of respiration) is removed via the PLACENTA. Hence, Gas exchange occurs through the placenta.
