Questions

A star is a self luminous astronomical object and shines due to internal radiation from the enrgy sources. All stars are held together by their own gravity called Gravitational force.

Indian Olympic Association (IOA) chooses P.V. Sindhu as the flag-bearer of the Indian contingent for the opening ceremony of the Gold Coast Commonwealth Games.

The opening ceremony will be held on April 4, 2018.

The US state California's  economy has surpassed that of the UK to become the world’s fifth largest, according to new federal data released.

With a GDP of $2.7 trillion, California is now only behind the US, China, Japan and Germany.

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.