The average speed is calculated using the following formula
Where

T = 298 K [room temperature]
m = mass of each molecule of oxygen
mass of one mole of oxygen molecules = 32 g / mol
mass of one molecule of oxygen will be = 
mass of one molecule of oxygen will be = 
putting values
average speed = 
Average speed = 482.19 m / s
average speed = 1735.8 km / h
so approx = 1700 km/h
(a) Matter cannot be created and destroyed by a chemical reaction.
Explanation:
(a) Matter cannot be created and destroyed by a chemical reaction. (correct)
The number and type of atoms entering the chemical reaction are the same with the number and type of atoms leaving the chemical reaction.
(b) The reactants are the same substance as the products. (wrong)
You may see in the reaction that we have as reactants zinc and hydrochloric acid which react to form the products, zinc chloride and hydrogen.
(c) The number of molecules in the reactants are equal to the number of molecules in the products. (wrong)
As reactants we have 2 hydrochloric acid (HCl) molecules and as products 1 hydrogen (H₂) molecule. Zn is a metal and ZnCl is a salt.
(d) The atoms on the reactants side are changed into different atoms on the products side. (wrong)
The number and type of atoms entering the chemical reaction are the same with the number and type of atoms leaving the chemical reaction.
Learn more about:
balancing chemical equations
brainly.com/question/13695436
#learnwithBrainly
To squeeze a gas into a dmaller place is to compress it.
Answer:
<h2>30.2 g</h2>
Explanation:
The mass of a substance when given the density and volume can be found by using the formula
mass = Density × volume
volume = final volume of water - initial volume of water
From the question
volume = 35.9 ml - 25.8 ml = 10.1 mL
We have
mass = 2.99 × 10.1 = 30.199 g
We have the final answer as
<h3>30.2 g</h3>
Hope this helps you