Answer:There are, however, other forms of empirical evidence that support the theory of evolution. The fossil record, anatomical and embryological homologous, and genetic similarities are also used to support the theory of evolution. Many pieces of evidence support the theory that birds and dinosaurs are related.
Explanation:hope i am helpful
Answer:
No photoelectric effect is observed for Mercury.
Explanation:
From E= hf
h= Plank's constant
f= frequency of incident light
Threshold Frequency of mercury= 435×10^3/ 6.6×10^-34 × 6.02×10^23
f= 11×10^14 Hz
The highest frequency of visible light is 7.5×10^14. This is clearly less than the threshold frequency of mercury hence no electron is emitted from the mercury surface
Answer:
The molecular formula is C12H18O3
Explanation:
Step 1: Data given
The empirical formula is C4H6O
Molecular weight is 212 g/mol
atomic mass of C = 12 g/mol
atomic mass of H = 1 g/mol
atomic mass of O = 16 g/mol
Step 2: Calculate the molar mass of the empirical formula
Molar mass = 4* 12 + 6*1 +16
Molar mass = 70 g/mol
Step 3: Calculate the molecular formula
We have to multiply the empirical formula by n
n = the molecular weight of the empirical formula / the molecular weight of the molecular formula
n = 70 /212 ≈ 3
We have to multiply the empirical formula by 3
3*(C4H6O- = C12H18O3
The molecular formula is C12H18O3
.5 mol of A will be left over since 1.5 mol of A will be used for every 3 mol of B due to the 2:1 ratio established by the formula.
The statement is true. The octet rule refers to the general rule of thumb wherein atoms of main-group elements tend to bond with other atoms in such a way that each atom possesses eight electrons (octet) in their valence shell. They tend to form the same electronic configuration as the noble gases. However, there are some exceptions to this rule. One of which is silane, SiH₄. A hydrogen atom only has 1 valence electron and needs another electron to complete its energy level. This is unlike other atoms, for example, carbon which has 4 valence electrons and needs to form 4 covalent bonds to fill its energy levels. Thus, 4 hydrogen atoms need only 4 more electrons. This is given by the silicon atom which has 4 valence electrons. Therefore, when a silicon atom is bonded to 4 hydrogen atoms, the resulting molecule, SiH₄, is a stable one.
