1.4mL
Explanation:
Given parameters:
Mass of object = 3.5g
density = 2.5g/mL
Unknown:
Volume of the object = ?
Solution:
Density is the mass per unit volume of a body. It is an intensive property that is the same for the same substances.
Density = 
since the volume is unknown; we make it the subject of the formula;
Volume = 
Volume = 
Volume of the object = 1.4mL
learn more:
Density brainly.com/question/4825250
#learnwithBrainly
Answer:
what? what's the full question?
Answer: similar: Protons and neutrons have approximately the same mass, about 1.67 × 10-24 grams. Different:Protons are a type of subatomic particle with a positive charge. And Neutrons are a type of subatomic particle with no charge (they're neutral).
Explanation:
hope that helped
One of the differences I can think of is that hydrogen is no longer listed as a group I element.
According to the mendeleev tables that I looked up, hydrogen is catorgrized as a group I element, along with Lithium, sodium, Potassium etc. However, nowadays, hydrogen does not belong to any groups in the periodic table. This is because there are arguments about whether hydrogen belongs to group I. Group I elements are all alkali metals, while hydrogen is not. However, some people says that hydrogen only have one outer shell electron so it should be in group I. Some people even say hydrogen should belong to group VII because it only needs one more electron in order to achieve the duplet of electrons.
Therefore as you may notice, hydrogen in modern periodic tables are put in the center of the periodic table on the top.
