Answer:
NaCl
Explanation:
because He which is helium gas its an element alone,
Cl which is chlorine is a single element,
B which is Boron and its a single element,
but NaCl which is simply called table sugar is the combination between Na, sodium and Cl, chlorine , so its called a compound not an element.
I think that the answer is A because if you think about water for an example. When water turns into ice, it's still technically water, just the molecules are frozen. The water is physically changed. It could also see why you think it is B but I don't think so completely. It doesn't really make sense to me. So I'd choose A. It's definitely not C or D.
180 km/s V= 25
explanation: i had the same assignment
Fuel cells work by passing hydrogen through the anode of a fuel cell and oxygen through the cathode. On the anode site, hydrogen molecules are split into electrons and protons. They have a high efficiency therefore these fuel cells are also considered to be very clean plus a fuel cells only by-products are electricity, excess heat, and water.
Answer:
We are given:
V(i) = 0.3 L V(f) = 0.36 L
P(i) = x pa P(f) = 400 pa
T(i) = T(f) = 293 k
Using the gas formula:
PV = nRT
Since n , R and T are constant,
PV = k (where k is a constant)
Hence we can say that:
P(i) * V(i) = P(f) * V(f)
x * 0.3 = 0.36 * 400
x = 14.4/0.3
x = 480 pascals
Hence the initial pressure is 480 pascals
Converting to Kpa, we have to divide by 1000
Initial pressure (Kpa) = 0.48
