Answer:
15.2 mL
Explanation:
First we calculate the volume of the copper
when this volume of copper is added to the water, the water level will rise by the level of the volume of copper. So the final volume is:
14.6 mL + 0.5580 mL = 15.158 mL
Since the measuring cylinder is graduated to one decimal place , we can round this up to 15.2 mL
Answer:
<em></em>
<em></em>
- <em>The halogens posses </em><u><em>seven </em></u><em>valence electrons</em>
Explanation:
- <em>Valence electrons </em>are the electrons in the outermost orbitals of the atoms, which are the orbitals with the highest main energy level (principal quantum number).
- Halogens are the elements of the group 17 of the periodic table: F, Cl, Br, I, At.
- You can tell the number of valence electrons of the representative elements from the number of the group to which they belong. For the representative elements, the number of valence electrons equal the unit digit of the group number.
This table summarizes it:
Group number number of valence electrons
1 1
2 2
13 3
14 4
15 5
16 6
17 7
18 8
- So, in conclusion, <em>the halogens possess 7 valence electrons.</em>
Answer:
Disagree
Agree
Agree
Disagree
Explanation:
A chemical change is one in which a new kind of substance is formed. It is always accompanied by energy changes.
- It is wrong to assert that all chemical changes are dangerous. In our body system, chemical changes are constantly happening.
- Chemical changes shows the law of conservation of mass in that the amount of reactants and products are always the same.
- Chemical reactions occur when two substances are chemically combined together.
- Not all dissolution reaction are chemical changes. For example, when sugar dissolves in water, it is not a chemical change.
Answer:
Vertebrae
Explanation:
Vertebrae are the 33 individual bones that interlock with each other to form the spinal column. The vertebrae are numbered and divided into regions: cervical, thoracic, lumbar, sacrum, and coccyx (Fig. 2). Only the top 24 bones are moveable; the vertebrae of the sacrum and coccyx are fused.
