We use radiowaves all the time because they are harmless. (as far as we know, although bees are dying and know one knows why, perhaps all the waves we use do have a negative effect)
Can I get a brainliest, please?
54.936 grams of NaCl will be produced from 33.0 g of Na and 34.0 g of Cl.
Explanation:
Data given:
mass of Na = 33 grams
mass of 
= 24 grams
atomic mass of Na = 23 grams/moles
atomic mass of Cl = 70 grams/mole
mass of NaCl formed =?
atomic mass of NaCl = 58.44 gram/mole
balanced chemical reaction:
2Na + ⇒ 2NaCl
number of moles = 
putting the values in the equation:
number of moles of Na = 
= 0.69 moles
number of moles of chlorine gas = 
= 0.47 moles
limiting reagent is chlorine gas in the reaction
from the balanced chemical reaction:
1 mole of chlorine gas reacts to form 2 moles of NaCl
then 0.47 moles of chlorine gas will form x moles
= 
x = 0.94 moles of NaCl is formed.
mass = atomic mass x number of moles
mass = 58.44 x 0.94
= 54.936 grams of NaCl is produced.
Helium - 4 isotope has 2 protons and 2 neutrons.
Its atomic number is 2 (the number of protons). Atomic number is the number of protons in the atom of an element and it identifies the element. All the isotopes of an element have the same atomic number (same number of protons). So, all the isotopes of hellium have 2 protons.
The number 4 that identifies the helium - 4 isotope is the mass number, i.e. the number of protons plus the number of neutron. So, helium-4 isotope has 2 protons and 2 neutrons. While, other isotopes of helium have 2 protons but different number of neutrons.
The atomic number enable us to deduce the number of electrons in an atom because the atoms are neutral, which implies that the positive and negative charge are equal. Given that the magnitude of the charge of electons and protons are equal but the sign is opposed (protons are positve and electrons are negative) the number of electrons in the atom equals the number of protonts. That is why the atomic number is also the number of electrons of the atom.
Answer:
14.32g
Explanation:
Initial temperature = 83.8°C
Final temperature = 77.1°C
Temperature change, ΔT = 83.8°C - 77.1°C = 6.7
Heat, H = 167J
Specific heat, c = 1.740J/g °C
m = ?
All these parameters are related with the equation below;
H = mcΔT
m = H / cΔT
m = 167 / (1.740 * 6.7)
m = 167 / 11.658 = 14.32g
