<span>Dr. Garcia should compare fly cells to human cells.
</span>
Answer: The correct statements are ; A and B.
Explanation:
The strength of the magnetic field(B) in an electromagnet can be calculated using formula:
= Relative permeability
N = number of turns
I = Current in the wire of the solenoid
L = length of the solenoid or electromagnetic
As we can see from the formula:
So, by increasing the turns and increasing current flowing through wire one can increase the strength of an electromagnet.
Hence, the correct statements are ; A and B.
Dipole interactions are observed in covalent bonds. In ionic bonding, permanent transfer of electrons occurs and due to this dipole-dipole interactions are not observed. In covalent bonding, electron cloud is shared between 2 atoms. If this electron cloud is not shared equally between them, polarities are formed in a molecule. And hence we say that the molecule is polar. For a molecule to be polar, there should be electronegativity difference between them. Atom with greater electronegative attracts electron cloud more towards itself whereas atom with lesser electronegative attracts electron cloud less. But there is no permanent transfer of electrons. Due to this electronegativity differences, atom with more electronegative gains partial negative charge and atom with lesser electronegative value gains partial positive charge. The charge is partial because there is no complete transfer of electrons.
Answer: C. no new substances
are formed<span>
</span><span>
<span>In the
physical change of matter, there is no new substance that is formed. It is only
the appearance of the matter that is being changed and not its chemical
composition. Cutting, tearing and grinding are only some of the examples that
exhibit physical change. </span></span>
