Answer:
12.5%
Explanation:
Initial percentage of carbon 14 = 100%
Final percentage = ?
Time passed = 17.1 * 1000 years = 17100 years
Half life of carbon 14 = 5,730 years.
So how many Half lives are in 17100 years?
Number of Half lives = Time passed / Half life = 3.18 ≈ 3
First Half life;
100% --> 50%
Second Half life;
50% --> 25%
Third Half life ;
25% --> 12.5%
Electronegativity of an element decreases as we move down a group on the periodic table and electronegativity increases while moving from left to right across a period on the periodic table.
Explanation:
- The electronegativity increases as we move from left to right across a period because from left to right across a period, the nuclear charge is increasing Hence the attraction for the valence electrons also increases.
- As we move down a group, the atoms of each element have an increasing number of energy levels. The distance between the nucleus and valence electron shell increases and reduces the attraction for valence electrons. Hence electronegativity decreases as we move from top to bottom down a group.
Answer: well i guess we can say that is a scale used to specify the acidity or basicity of an aqueous solution and it is important to keep ph of hot tub water between 7 and 7.6 because if it is not balanced the water can negatively affect your tub.
Explanation:
pH is an extremely important chemical level to maintain in your spa's water chemistry. A high pH or a low pH will spell trouble for you and your spa. On the pH scale, a reading of 7.4-7.6 indicates perfectly balanced pH. Any number lower than 7.4 means that your water is now considered “acidic”.
Answer:
Mass of Sodium = 574.75 g
Mass of Chlorine = 886.25 g
Explanation:
The balance chemical equation for the synthesis of NaCl is,
2 Na + Cl₂ → 2 NaCl
Step 1: <u>Find out moles of each reactant required,</u>
According to balance chemical equation,
2 moles of NaCl is produced by = 2 moles of Na
So,
25 moles of NaCl will be produced by = X moles of Na
Solving for X,
X = 25 mol × 2 mol / 2 mol
X = 25 moles of Na
Similarly for Cl₂,
According to balance chemical equation,
2 moles of NaCl is produced by = 1 mole of Cl₂
So,
25 moles of NaCl will be produced by = X moles of Cl₂
Solving for X,
X = 25 mol × 1 mol / 2 mol
X = 12.5 moles of Cl₂
Step 2: <u>Convert each moles to mass as;</u>
Mass = Moles × Atomic Mass
For Na,
Mass = 25 mol × 22.99 g/mol
Mass = 574.75 g
For Cl₂,
Mass = 12.5 mol × 70.90 g/mol
Mass = 886.25 g
