periodic table

If the element copper has 29 protons and 29 electron and has an atomic mass of about 64. how many neutrons does it have?

35

Rounded to the nearest whole number, how many electrons are in an atom of zirconium?

40

Which statements accurately describe trends found in the periodic table?

Henry Moseley established a periodic table that arranges the elements by atomic number.The atomic number increases from left to right on the periodic table.Metalloids have the characteristics of both metals and nonmetals.

Which two chemists organized elements based on properties such as how the elements react or whether they are solid or liquid?

Lavoisier and Döbereiner

While developing his periodic table, Dmitri Mendeleev broke his own rule and placed the element tellurium before iodine in the group. He did this even though tellurium's atomic mass was known to be greater than iodine's. In his notes, Mendeleev stated that he expected tellurium to have a lower atomic mass than iodine. However, all measurements continue to show that tellurium has a greater atomic mass than iodine even though tellurium acts like it has a lower atomic mass. What is the most likely reason that Mendeleev placed tellurium before iodine?

Mendeleev observed that tellurium has chemical properties like other elements in its group, and he did not know that neutrons cause the greater atomic mass.

What is the major difference between the periodic table created by Dmitri Mendeleev and the one created by Henry Moseley?

Moseley arranged the elements in order of increasing atomic number.

The element phosporus is located to the right of the element magnesium along the same period in the periodic table. Which best describes the relationship of the elements?

Phosphorus has a larger atomic mass.

Dmitri Mendeleev and Henry Moseley developed their periodic tables about forty years apart. During that time, many discoveries in chemistry were made. Which fact was most likely discovered between the time of Mendeleev's table and the time of Moseley's table that helped Moseley develop his version?

The number of protons in an atom is different than the atom's total mass.

In an element's square on the periodic table, the number with the greatest numerical value represents the

atomic mass

Which is one piece of information that "9" gives about an atom of fluorine? The atomic mass is different than the atomic number, and the number of neutrons is the difference between the atomic mass and the atomic number.

atomic number

While looking at calcium (Ca) on the periodic table, a student needs to find an element with a greater atomic mass in the same period. Where should the student look?

directly to the right

A vertical column of elements in the periodic table is called a

group

As you move from left to right on the periodic table, the atomic number

increases

Atoms of elements in the same group have the same

number of valence electrons

A horizontal row of elements in the periodic table is called a

period

Elements in group 2 are all called alkaline earth metals. What is most similar about the alkaline earth metals?

which chemical properties they have