1. A. All the elements in the column have similar chemical properties.
2. Substances on the periodic table cannot be broken down into other substances and are therefore elements.
a. mol O₂=0.5
b. volume O₂ = 25 cm³
c. i. the total volume of the two reactants = 75 cm³
c. ii. the volume of nitrogen dioxide formed = 50 cm³
<h3>Further explanation</h3>
Reaction
2NO(gas) + O₂(gas) ⇒ 2NO₂ (gas)
a.
mol NO = 1
From the equation, mol ratio NO : O₂ = 2 : 1, so mol O₂ :

b.
From Avogadro's hypothesis, at the same temperature and pressure, the ratio of gas volume will be equal to the ratio of gas moles
Because mol ratio NO : O₂ = 2 : 1, so volume O₂ :

c.
i. total volume of reactants : 25 cm³+ 50 cm³=75 cm³
ii. the volume of nitrogen dioxide formed :
mol ratio NO : NO₂ = 2 : 2, so volume NO₂ = volume NO = 50 cm³
Answer:
0.5 moles of LiOH will absorb 5.6 L of 
Explanation:
According to law of conservation of mass, the sum of mass on the reactant side must be equal to the sum of mass on product side.
The balanced chemical equation is:

2 moles of LiOH absorb 1 mole of
i.e. 22.4 Liters at STP
0.5 moles of LiOH absorb
=
0.5 moles of LiOH will absorb 5.6 L of 
Answer:
Solid metal.
Explanation:
At room temperature, Chromium (Cr), a transition metal, is a solid.
Answer:
No
Explanation:
This is because light cannot not whiten Jayden's teeth but light can change materials by hearing it up. There are some substances or tooth paste that can be use to whiten the teeth because of the content they are made off which whitens the teeth. Some of it include baking soda, hydrogen peroxide toothpaste, tumeric toothpaste, toothpaste that contain fluoride.