decay rate is r= ln2/h. Radium-221 has a half-life of 30 seconds. How long will it take for 90% of a sample to decay = o-rt
LOTS OF POINTS PLZ HELP
Answer:
Exothermic reaction
Explanation:
Notice that the energy component is located on the right side of the reaction. The right side is always known as the product side. Whenever energy is located there, the reaction is known to give off energy - essentially, we can say that energy is a product, as well. Reactions that give off energy are known as exothermic reactions.
On the other hand, if the energy component was located on the left side, or reactant side, of the equation, it would be known as an endothermic reaction.
Here, it's exothermic.
Hope this helps!
Answer: Heat equation
Answer : The correct option is, (1) ions.
Explanation :
According to the Arrhenius concept, an acid is a type of substance which ionizes in water to gives ions (hydronium ions or hydrogen ions) and a base is a type of substance which ionizes in water to gives ions (hydroxide ions).
As we know that KOH is a base which ionizes in water to gives ions (hydroxide ions) and ions.
Hence, potassium hydroxide is classified as an Arrhenius base because KOH contains ions.
A black hole collapsed to form the sun; small planetary objects formed; small planetary objects collided with each other to form larger objects.
B.
Most of the dust and gas contracted into a central mass—the Sun; half the mass of the cloud condensed to form Jupiter; asteroids and comets crashed into the sun to form the smaller planets.
C.
A spinning cloud of dust began to compress to form the sun; small planetary objects formed; hydrogen and helium became concentrated in the outer solar system to form the outer planets.
D.
Gravitational force held the newly formed planets around the sun; small planetary objects formed; hydrogen and helium became concentrated in the outer solar system to form the outer planets.
The statement about the formation of the solar system that are true and in a correct order are Gravitational force held the newly formed planets around the sun; small planetary objects formed; hydrogen and helium became concentrated in the outer solar system to form the outer planets. The answer is letter D.
b) [Ha} < [A-]
c) [HA]=[A-]