If an object repels from another negatively charged object, the first object is

The first object must be negatively charged.

Explanation:

There are two types of charged particles: Positively charged and negatively charged.

Positively charged particles carry a positive charge negatively charged particles carry a negative charge.

We know that:

Like charges repel each other and unlike charges attract each other. This means that positive charge will be repelled by positive charge and it will be attracted by a negative charge.

In the question, an object is being repelled by another object which is negatively charged. Thus, the first object must carry the same charge as the other object.

Hence, the first object must be negatively charged.

  the grams     of oxygen gas   that can be produced     is 20.6   grams of o₂

calculation

2liclo₃ →   2 licl + 3 o₂

step 1:   find the moles of liclo₃

moles = mass÷ molar mass

from periodic table the molar mass of liclo₃ =6.9 +35.5   +(16 x3) =90.4 g/mol

moles=38.7 g÷90.4 g/mol=0.4281   moles

step 2:   use the   mole ratio   to calculate the moles of o2

from equation above, liclo₃: o₂   is 2: 3  

therefore the moles of   o₂=0.4281 moles x3/2 =0.6422   moles

step 3: find mass   of o₂

mass= moles x molar mass

from periodic table the   molar mass of   o₂ = 16 x2= 32 g/mol

mass=0.6422   moles   x   32 g/mol = 20.6 grams of o₂