Answer:
Decreases
Explanation:
An element's oxidation number decreases because it gained electrons.
The answer to this question would be: 3.125%
Half-life is the time needed for a radioactive molecule to decay half of its mass. In this case, the strontium-89 is already gone past 5 half lives. Then, the percentage of the mass left after 5 half-lives should be:
100%*(1/2^5)= 100%/32=3..125%
Answer:
16,,24Mg 17,,a24.1 18a mass number of the most abundant isotope
Explanation:
atomic number of Mg is 12 ,therefore its mass number should be the value that is very close to 24.
24.1 is the value of thee most abundant isotope.
4 3 and 5 are wrong:)
4 is true and 5 is false
4. insulators are really thick materials that keep electrons within their space.
For example, a charger the rubber is the insulators and the electrons are flowing inside of the charger so you don't get shocked.
5. without the force of attraction, there are no atoms:)
for number 3, its a trick question
Hope this helped!
(learned these this year so I didn't forget them:)
Answer:
8.934 g
Step-by-step explanation:
We know we will need a balanced equation with masses and molar masses, so let’s gather all the information in one place.
M_r: 192.12 44.01
H₃C₆H₅O₇ + 3NaHCO₃ ⟶ Na₃C₆H₅O₇ + 3H₂O + 3CO₂
m/g: 13.00
For ease of writing, let's write H₃C₆H₅O₇ as H₃Cit.
(a) Calculate the <em>moles of H₃Cit
</em>
n = 13.00 g × (1 mol H₃Cit /192.12 g H₃Cit)
n = 0.067 67 mol H₃Cit
(b) Calculate the <em>moles of CO₂
</em>
The molar ratio is (3 mol CO₂/1 mol H₃Cit)
n = 0.067 67 mol H₃Cit × (3 mol CO₂/1 mol H₃Cit)
n = 0.2030 mol CO₂
(c) Calculate the <em>mass of CO₂
</em>
m = 0.2030 mol CO₂ × (44.01 g CO₂/1 mol CO₂)
m = 8.934 g CO₂
