You would know a decomposition reaction occurred if the reactants separated. For example from AB → A+B.
Now if you look at your options only 1 works out for that equation. Letter A.
From the compound K2CO3 it split up to K2O +CO2
It cannot be letter B because synthesis/combination occurred. The same goes for letter C. Letter D, single displacement occurred.
Again, the answer is A.
Explanation:
The compass needle moved when the wire was connected to the battery. The important point here is that the needle is affected by the wire only when both ends of the wire are connected to the battery because only at this time is current flowing through the circuit.
Answer:



Explanation:
Notice that this is a circuit with resistors R1 and R2 in parallel, connected to resistor R3 in series. It is what is called a parallel-series combination.
So we first find the equivalent resistance for the two resistors in parallel:

By knowing this, we can estimate the total current through the circuit,:

So approximately 0.17 amps
and therefore, we can estimate the voltage drop (V3) in R3 uisng Ohm's law:

So now we know that the potential drop across the parellel resistors must be:
10 V - 4.28 V = 5.72 V
and with this info, we can calculate the current through R1 using Ohm's Law:

Answer:
<em>The volume of water is 3.5 cubic meter</em>
Explanation:
<u>Density
</u>
The density of a substance or material is the mass per unit volume. The density varies with temperature and pressure.
The formula to calculate the density of a substance of mass (m) and volume (V) is:

We are given the density of water as
.It's required to find the volume of m=3,500 kg of water. Solving for V:



The volume of water is 3.5 cubic meter
Yaaaas, do you watch James Charles!?