We know that the oxygen (O2) causes a glowing
splint to reignite, however, let us check what is missing on the products side
of the chemical equation: <span>
KBrO3 → KBr + ?
As we see, oxygen (O2) is the element missing from the other
side. Therefore the balanced chemical
equation for this decomposition is as follows: </span>
<span>2KBrO3 → 2KBr + 3O2 </span>
Answer: Ice is melting due to the transfer of thermal energy from Jan's hand to ice.
Explanation: The melting of ice is a physical change and is happening when the thermal energy from Jan's hand is transferred to ice. Due to this energy transfer, the particles of ice starts to move faster and hence, making the ice melt.
In this, the physical state of ice is changing from solid to liquid state.

<span>Methane, answer c, can be decomposed by chemical means because methane is a compound. Methane is made up of one atom of carbon and four atoms of hydrogen. Compounds can be broken down. Cobalt, krypton, and zirconium are all elements, and elements cannot be chemically decomposed.</span>
Answer : The mass of 7.0 m chain is, 15.12 kg
Explanation :
As we are given that,
The weight of the chain per unit length = 2.16 kg/m
Now we have to determine the mass of chain for 7.0 m length.
As, the mass of 1 m length of chain = 2.16 kg
So, the mass of 7.0 m length of chain = 
= 15.12 kg
Therefore, the mass of 7.0 m chain is, 15.12 kg
Answer:
Scandium(III) fluoride, ScF3, is an ionic compound. It is slightly soluble in water but dissolves in the presence of excess fluoride to form the ScF63− anion.
hope it will help you......