Remember that the:
1. Vertical columns are groups and families
2. Horizontal columns are periods
3. Period 1 has 2 e-, 2 has 8 e-, 3 has 8 e-, and 4 has 18 e-
3.The number on top of the groups/families shows what group it is on (ex. 1A, 2A, 3B, 4B, etc) and the number on top of that indicates the number of the same thing (what group it is)
⇒ ex. 1A has 1 val e-. 2A has 2 val e-. 3A has 3 val e- ( and rest goes up until 8A). Note: I skipped the transitions metals since they don't have accurate amount of val e-.
4. Know which is the mass number, atomic number, symbol, or name.
5. Where the metals, non- metals, and metalloids are located.
6. Elements on the same groups have similar properties.
7. The first group is Akali Metals and are very unstable and very reactive
8. Second group is Akaline Earth Metals
9. The middle, groups 3-12 are Transition Metal
10. Group 13 is the Boron Family.
11. Group 14 is the Carbon Family
12. Group 15 is the Nitrogen Family
13. Group 16 is the Oxygen Family.
14. Group 17 is the Halogen, salt families
15. Group 18 is the Noble Gases, and are very stable and not reactive.
I hope this helps. :)
Answer:
Explanation:
(KF)2(Al2O3)3(SiO2)6(H2O)
molecular formula
K₂F₂Al₆Si₆O₂₂H₂
2 x 39 + 2 x 19 + 6 x 27 + 6 x 28 + 22 x 16 + 2 x 2
= 78 + 38 + 162+ 168+ 352+ 4
= 802
Percentage of K = 78 x 100 / 802
= 9.72 %
Percentage of F = 38 x 100 / 802
= 4.74 %
Percentage of Al = 162 x 100 / 802
= 20.2 %
Percentage of Si = 168 x 100 / 802
= 20.9 %
Percentage of O = 352 x 100 / 802
= 43.9 %
Percentage of H = 4 x 100 / 802
= .54 %
Answer:
Taking reading of the volume level of liquid in a buret while it is inclined leading to parallax error
Explanation:
Practices that will not help you make accurate volume reading on a buret are
1. Leaving air bubbles buret tip or in the stopcock
2. Error due to parallax: Taking volume reading while looking at the scale of an inclined buret. Looking down the buret gives it an appearance of a higher reading than actual reading while up towards the meniscus will make it look lower than the actual value
3. Pouring in the liquid too rapidly into the buret forming droplets on the inner walls of the buret which can alter the volume reading of the buret when the drops settle into the remaining liquid in the buret
It was first proposed by J. J. Thomson in 1904.
helium, beryllium, magnesium, calcium, strontium, barium, radium. i believe any of these are proper answers.
