I think the answer to this A but I’m not rlly sure
Option no. 2 subtracting the atomic number from the mass number
Example: Zn - 65 atomic weight or mass/mass number
30 atomic number
65-30 = 35 number of neutrons
Answer:
5230J
Explanation:
Mass (m) = 250g
Initial temperature (T1) = 25°C
Final temperature (T2) = 30°C
Specific heat capacity (c) = 4.184J/g°C
Heat energy (Q) = ?
Heat energy (Q) = Mc∇T
Q = heat energy
M = mass of the substance
C = specific heat capacity
∇T = change in temperature = T2 - T1
Q = 250 × 4.184 × (30 - 25)
Q = 1046 ×5
Q = 5230J
The heat energy required to raise the temperature of 250g of water from 25°C to 30°C is 5230J
Answer:
it has an equal number of neutrons and electrons
Explanation:
Number of protons always equal number of electron, but that's the case with a neutral atom. A neutral atom is an atom of any element that has no electric charge over it. This implies that it has same number of protons and electrons in it.
The complete table is inserted.
A table is given,
Formulas used:
pH= -log(H⁺)
pOH= -log(OH⁻)
pH+ pOH=14
Calculations:
For A: (H⁺)=2×10⁻⁸M
Using the pH formula:
pH= -log(H⁺)=-log(2×10⁻⁸)=7.69
pOH=14 - 7.69=6.3
Calculating OH concentration,
pOH= -log(OH⁻)
6.3= -log(OH⁻)
(OH⁻)=5.011×10⁻⁷M
Hence, the nature of A is basic.
Similarily,
For B,
(OH⁻)=1×10⁻⁷
Using the pH formula:
pOH= -log(OH⁻)= -log(1×10⁻⁷)=7
pH=14-7=7
Calculating H concentration,
pH= -log(H⁺)
7= -log(H⁺)
(H⁺)=1×10⁻⁷M
Hence, the nature of B is neutral.
Similarily,
For C,
pH=12.3
Using the pH formula:
pOH=14-12.3=1.7
Calculating H concentration,
pH= -log(H⁺)
12.3= -log(H⁺)
(H⁺)=5.011×10⁻¹³M
Calculating OH concentration,
pOH= -log(OH⁻)
1.7= -log(OH⁻)
(OH⁻)=1.99×10⁻²M
Hence, the nature of C is Basic.
Similarily,
For D,
pOH=6.8
Using the pH formula:
pH=14-6.8=7.2
Calculating H concentration,
pH= -log(H⁺)
7.2= -log(H⁺)
(H⁺)=6.309×10⁻⁸M
Calculating OH concentration,
pOH= -log(OH⁻)
6.8= -log(OH⁻)
(OH⁻)=1.58×10⁻⁷M
Hence, the nature of D is basic.
Learn more about the acid and bases here:
brainly.com/question/16189013
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