Answer:
Element symbol Cu
Number of protons 29
Number of electrons 28
Explanation:
To get the element symbol, we need the name of the element. To correctly identify the name of the element, we need the proton number.
Now the mass number is 65 and the number of neutrons is 36. The number of protons is this the mass number minus the number of neutrons. This equals 65 - 36 = 29 protons.
The element with 29 protons is copper Cu.
Now to get the number of electrons, for an electrically neutral atom , the number of electrons equals the number of protons. But here, the atom is not electrically neutral anymore as it has now formed a univalent positive ion of +1.
To form a positive ion, you have to do so by losing electrons. The atom in question here has just lost one electron. Thus, our of the 29, it is left with only 28 electrons.
Answer:
The law of the conservation of mass states that matter is neither created nor destroyed, only converted to other forms. Therefore, the mass never changes, even if its appearance does.
Explanation:
Answer:
1.8 × 10² cal
Explanation:
When 0.32 g of a walnut is burned, the heat released is absorbed by water and used to raise its temperature. We can calculate this heat (Q) using the following expression.
Q = c × m × ΔT
where,
c: specific heat capacity of water
m: mass of water
ΔT: change in the temperature
Considering the density of water is 1 g/mL, 58.1 mL = 58.1 g.
Q = c × m × ΔT
Q = (1 cal/g.°C) × 58.1 g × 3.1°C
Q = 1.8 × 10² cal
Na₃PO₄ -----> 3Na(+) + PO₄(3-)
y-y.......................3y...........y
3y = 1.2
y = 0,4M
Na₃PO₄ -----> 3Na(+) + PO₄(3-)
0,4-0,4..............1,2..........0,4
0.........................1,2..........0,4
C = n/V
n = C×V
n = 0,4×0,65L
n = 0,26 mol Na₃PO₄
mNa₃PO₄: (23×3)+31+(16×4) = 164 g/mol
164g ----- 1 mol
Xg -------- 0,26 mol
X = 164×0,26
X = 42,64g Na₂SO₄
