Answer:
The properties of matter include any traits that can be measured, such as an object's density, color, mass, volume, length, malleability, melting point, hardness, odor, temperature, and more. We need to study all these traits since every single object around us, including us, is made of matter. Without matter we wouldn't exist; it would be infinite darkness everywhere.
Answer:
7.96g, 33.79%
Explanation:
I'll try my best to explain the entire process behind this question ;)
From the question, you can write the reaction

Now, there are a few reasons it is like this. Oxygen is a diatomic element, meaning it doesn't and can't exist as just O. It exists as O₂. To balance, this, double the amount of water and hydrogen so there is an equal amount of each element on both sides of the reaction (4 H's, 2 O's on the reactant side, and 4 H's, 2 O's on the product side).
From this we can get a mole-to-mole ratio.
Onto the stoichiometry. Our goal in this is to convert from grams of water to grams of hydrogen, and we do so with a mole to mole ratio.

Basically, what I did was divide by water's molar mass to get moles of water, multiplied by the mole-to-mole ratio (2:2) to get moles of H2, and then multiplied by H2's molar mass to get what should be the amount of H2 produced by the reaction.
For percent yield, you can calculate it is such:

Plug the numbers in:

So, the percent yield is 33.79%
Don't understand the text, but water always freezes at 0°C as long as its water.
The answer is 10. Each capital letter is an atom. The tiny numbers represent how many atoms of that type
Answer:
2.772 seconds
Explanation:
Given that;
t1/2 = 0.693/k
Where;
t1/2 = half life of the reaction
k= rate constant
Note that decomposition is a first order reaction since the rate of reaction depends on the concentration of one reactant
t1/2 = 0.693/2.5 x 10-1 s-1
t1/2= 2.772 seconds