Answer:
1. the group number of sodium is 1 and it is a metal
2. the group number of helium is 18 and it is a nonmetal
3. the group number of iodine is 17 and it is a nonmetal
4.the group number of calcium is 2 and it is a metal
5. lithium has similar properties to potassium
6. calcium has similar properties to magnesium
7. neon has similar properties to xenon
8. Iodine has similar properties to chlorine
The volume of the liquid in this diagram shown above would be equal to 36.5 mL.
<h3>What is a
graduated cylinder?</h3>
A graduated cylinder is also known as measuring cylinder and it can be defined as a narrow, cylindrical piece of laboratory equipment with marked lines, which are used to measure the volume of a liquid.
In order to take a reading for the measurement of the volume of a liquid such as water, you should ensure that your eye level is even with the center of the meniscus.
In this scenario, the volume of the liquid in this diagram would be 36.5 mL because each of the small lines on the graduated cylinder measures 0.5 mL.
Read more on graduated cylinder here: brainly.com/question/24869562
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Answer:
Electrons have negative charge.
There will be 7.5 g of Be-11 remaining after 28 s.
If 14 s = 1 half-life, 28 s = 2 half-lives.
After the first half-life, ½ of the Be-11 (15 g) will disappear, and 15 g will remain.
After the second half-life, ½ of the 15 g (7.5 g) will disappear, and 7.5 g will remain.
In symbols,
<em>N</em> = <em>N</em>₀(½)^<em>n</em>
where
<em>n</em> = the number of half-lives
<em>N</em>₀ = the original amount
<em>N</em> = the amount remaining after <em>n</em> half-lives
