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Arada [10]
3 years ago
6

PLEASE ANSWER!!!!!!!endothermic and exothermic reactions lab report

Chemistry
2 answers:
miv72 [106K]3 years ago
6 0
Exothermic is put heat out endothermic is in taking heat in
nexus9112 [7]3 years ago
6 0
<span>Exothermic is a reaction/ process accompanied by the release of heat.
Endothermic is </span><span>a reaction/ process accompanied by/ or requiring the absorption of heat.
</span>
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Hurry PLEASE HELP!
avanturin [10]

B. 11,540

<h3>Further explanation </h3>

The atomic nucleus can experience decay into 2 particles or more due to the instability of its atomic nucleus.  

Usually radioactive elements have an unstable atomic nucleus.  

General formulas used in decay:  

\large{\boxed{\bold{N_t=N_0(\dfrac{1}{2})^{t/t\frac{1}{2} }}}

T = duration of decay  

t 1/2 = half-life  

N₀ = the number of initial radioactive atoms  

Nt = the number of radioactive atoms left after decaying during T time  

Nt=25 g

No=100 g

t1/2=5770 years

\tt 25=100\dfrac{1}{2}^{T/5770}\\\\\dfrac{1}{4}=\dfrac{1}{2}^{T/5770}\\\\2=T/5770\rightarrowT=11540~years

7 0
3 years ago
PLZ HELP IT BEING TIMED!!!!!! PLZ ANSWER!!!!!
Wittaler [7]

Answer:

YIKES. a bit late. Answers include 1, 2, 3

Explanation:

6 0
2 years ago
What is the difference between atom and it’s ion ?
Sati [7]
Answer:
D. Number of electrons
8 0
3 years ago
A sample of pure lithium chloride contains 16% lithium by mass. What is the % lithium by mass in a sample of pure lithium carbon
Anna35 [415]

Answer:

Percentage lithium by mass in Lithium carbonate sample = 19.0%

Explanation:

Atomic mass of lithium = 7.0 g; atomic mass of Chlorine = 35.5 g; atomic mass of carbon = 12.0 g; atomic mass of oxygen = 16.0 g

Molar mass of lithium chloride, LiCl = 7 + 35.5 = 42.5 g

Percentage by mass of lithium in LiCl = (7/42.5) * 100% = 16.4 % aproximately 16%

Molar mass of lithium carbonate, Li₂CO₃ = 7 * 2 + 12 + 16 * 3 =74.0 g

Percentage by mass of lithium in Li₂CO₃ = (14/74) * 100% = 18.9 % approximately 19%

Mass of Lithium carbonate sample = 2 * 42.5 = 85.0 g

mass of lithium in 85.0 g Li₂CO₃ = 19% * 85.0 g = 16.15 g

Percentage by mass of lithium in 85.0 g Li₂CO₃ = (16.15/85.0) * 100 % = 19.0%

Percentage lithium by mass in Lithium carbonate sample = 19.0%

3 0
3 years ago
What is the equation for density?<br> O D= m<br> V<br> OD=V<br> m<br> OD=m<br> OD=mv²
frosja888 [35]

Answer:

D = m/V

Explanation:

Density represents the following ratio:

Density (D) = mass (m) / volume (V)

In this formula, the volume is being divided from the mass. The typical units for mass is grams and the unit for volume is milliliters.

4 0
2 years ago
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