Element? I'm quite not sure but...Hope this helps!
Answer:
the answer is 10
Explanation:
Al2 is 2 atoms by itself
(SiO3)2 is 8 because Si is a single atom and O3 is 3 oxygen atoms but because of the subscript outside of the parentheses it doubles and becomes 2 and 6 respectively
Answer:
They have the same number of atoms. = YES
They have different masses. = YES
Explanation:
1 mol of beryllium
• 1 mol of salt
beryllium = Be = Atomic mass: 9.012182
salt = NaCl = Molar mass: 58.44 g/mol
1 mol of water
• 1 mol of hydrogen
water = H2O = Molar mass: 18.01528 g/mol
hydrogen = H = 1g/mole
Which statement is true about these substances?
They have exactly the same mass. = NO
They have different numbers of particles = NO
They have the same number of atoms. = YES
They have different masses. = YES
Avogadro constant means the number of units in one mole of any substance (defined as its molecular weight in grams) is equal to 6.02214076 ×
.
power = work/time
watt = joule/sec
a) power = 0.10 watt = 0.1joules/sec
work = power * time
= 0.10 * 1 =0.1joules
work is northing but energy
therefore energy is 0.1joules
according to planks quantum theory E = nhν where nis the no. of photons ; h is planks constant; ν isfrequency
hence, n = E/hν
or n = Eλ/hc (ν = c/λ)
n = (0.1*700*10^-9)/6.625*10^-34*3*10^8 = 0.3522*10^18photons
b) similar to the above calculation
here E = 1.0joules
n = (1.0*700*10^-9)/6.625*10^-34*3*10^8 = 0.3522*10^17photons