The other dude is rude wrong
The correct answer is Dmitri Mendeleev
Answer:
Na sodiops los elementos químicos se representan como el átomo, el núcleo, donde se necuentran los protones y neutrones van dentro, los electrones afuera, girando de forma elíptica alrededor del núcleo. ... por ejemplo el oxígeno numero atómico 8, tiene 8 protones y 8 electrones. el número de neutrones es diferente.
Explanation:
Answer:
pH = 5.7
Explanation:
pH = -log[H^+]
For HCl pH = -log[HCl] = - log [2.10 x 10⁻⁶ ] = 5.7
Answer:
12.50g
Explanation:
T½ = 2.5years
No = 100g
N = ?
Time (T) = 7.5 years
To solve this question, we'll have to find the disintegration constant λ first
T½ = In2 / λ
T½ = 0.693 / λ
λ = 0.693 / 2.5
λ = 0.2772
In(N/No) = -λt
N = No* e^-λt
N = 100 * e^-(0.2772*7.5)
N = 100*e^-2.079
N = 100 * 0.125
N = 12.50g
The sample remaining after 7.5 years is 12.50g
