Questions

Protons carry a positive electrical charge, electrons carry a negative electrical charge and neutrons carry no electrical charge at all. The protons and neutrons cluster together in the central part of the atom, called the nucleus, and the electrons 'orbit' the nucleus.

Electric current produces a magnetic field. This magnetic field can be visualized as a pattern of circular field lines surrounding a wire.

During most of the cell cycle, interphase, the chromosomes are somewhat less condensed and are not visible as individual objects under the light microscope. However during cell division, mitosis, the chromosomes become highly condensed and are then visible as dark distinct bodies within the nuclei of cells. The chromosomes are most easily seen and identified at the metaphase stage of cell division and most of the chromosome images in this gallery are pictures of metaphase chromomosomes.

The cell division takes place in mitosis stage.

The boiling point of the compounds depend on the number of carbons in them. Hexane has 6, Pentane has 5 and Propane has 3 carbons. As Hexane is with 6 carbons it has highest boiling point and next Pentane with 5 and lowest Propane with 3. 

In chemistry, the term transition metal has three possible meanings: The IUPAC definition defines a transition metal as "an element whose atom has a partially filled d sub-shell, or which can give rise to cations with an incomplete d sub-shell".

Any of the set of metallic elements occupying a central block (Groups IVB–VIII, IB, and IIB, or 4–12) in the periodic table, e.g. iron, manganese, chromium, and copper. Chemically they show variable valency and a strong tendency to form coordination compounds, and many of their compounds are coloured.

Here in the given options, only iron (Fe) is a transition metal since Strontium is an alkaline earth, arsenic is a metalloid, hydrogen is (normally) a diatomic gas.