Density = mass/volume
D = 40/80 = 0.5g
D= 0.5g
B because once the circuit is burned the lights will all go of
1. alpha particle
alpha particles are positively charged helium nuclei with weak penetrating power
Answer:
pressure of gas are constant describe the relationship between moles and temprature
If we have a neutral atom, then it has the same number protons and neutrons.
The number protons and neutrons for neutral atom shows atomic number.
"A neutral atom has an atomic number of 20" means that atom has 20 protons (that give charge "+ 20" ) and 20 electrons (that give charge "-20").
Answer is 20 electrons.