Answer:
<h2>mass = 10.72 g</h2>
Explanation:
Density of a substance can be found by using the formula
Making mass the subject we have
From the question
Density = 2.70 g/cm³
We assume that the aluminum is a cuboid
and volume of a cuboid is given by
Volume = length × width × height
length = 5.3 cm
width = 0.32 cm
height = 2.34 cm
Volume = 5.3 × 0.32 × 2.34 = 3.97 cm³
Substitute the values into the above and solve for the mass
We have
mass = 2.70 × 3.97
We have the final answer as
<h3>mass = 10.72 g</h3>
Hope this helps you
ANSWER:
4 a) Specific elements have more than one oxidation state, demonstrating variable valency.
For example, the following transition metals demonstrate varied valence states: 
, 
, 
, etc.
Normal metals such as 
also show variable valencies. Certain non-metals are also found to show more than one valence state 
4 b) Isotopes are members of a family of an element that all have the same number of protons but different numbers of neutrons.
For example, Carbon-14 is a naturally occurring radioactive isotope of carbon, having six protons and eight neutrons in the nucleus. However, C-14 does not last forever and there will come a time when it loses its extra neutrons and becomes Carbon-12.
5 a) 
→ 
5 b) 
→ 
5 c) 
→ 
(already balanced so don't need to change)
5 d) 
→ 
5 e) 
→ 
EXPLANATION (IF NEEDED):
1. Write out how many atoms of each element is on the left (reactant side) and right (product side) of the arrow.
2. Start multiplying each side accordingly to try to get atoms of the elements on both sides equal.
EXAMPLE OF BALANCING:
Answer:
Pyrophoricity is a property of metals and oxides of lower oxidation states, including radioactive ones, in which they spontaneously ignite during or after stabilization.
Answer : The number of moles in 369 grams of calcium hydroxide is, 4.98 moles
Explanation : Given,
Mass of calcium hydroxide = 369 g
Molar mass of calcium hydroxide = 74.093 g/mole
Formula used :
Now put all the given values in this formula, we get the moles of calcium hydroxide.
Therefore, the number of moles in 369 grams of calcium hydroxide is, 4.98 moles
Answer:
3.41 x10⁶ torr
Explanation:
To solve this problem we need to remember the equivalency:
1 torr = 133.322 Pa
Then we can proceed to<u> convert 4.55×10⁸ Pa into torr.</u> To do that we just need to multiply that value by a fraction number, putting the unit that we want to convert <em>from</em> in the <em>denominator</em>, and the value we want to convert <em>to</em> in the <em>numerator</em>:
4.55x10⁸ Pa * 
3.41 x10⁶ torr
