activity 3

Dmitri Mendeleev ________.

-helped in the discovery of missing elements by predicting their behavior -developed the basis of our modern periodic table -predicted the existence of elements not yet discovered

Which chemical family is composed almost entirely of synthetic elements?

Actinides

Which element would have chemical properties the most similar to chlorine (Cl)?

Br

Which of the following elements are in the same group as silicon (Si)?

C and Sn

Strontium, Sr (number 38), is especially dangerous to humans because it tends to accumulate in calcium-dependent bone marrow tissues (calcium, Ca, number 20). This fact relates to the organization of the periodic table in that strontium and calcium are both ________.

Group 2 of the periodic table

Which elements are some of the oldest known?

The ones that have atomic symbols that don't match their modern atomic names: iron, gold, and copper.

Why isn't dirt listed in the periodic table?

The periodic table lists only elements made of one kind of material. Dirt is a mixture of elements and compounds.

Might you expect elemental sulfur, S8 , also to be a highly toxic and super stinky gas? Please explain.

The properties of a chemical compound, such as hydrogen sulfide, are uniquely different from the properties of the elements that come together to make that compound. Interestingly, elemental sulfur has low toxicity and only a slight odor.

Which of the following statements best describes an element?

a material consisting of only one type of atom

How did Lavoisier define an element?

a material that can't be broken down into simpler components

The repeating trends that take place when examining the elements are called ________.

periodicity

Dmitri Mendeleev's chart of elements ________.

placed elements together with similar properties

Which of the following describes a nonmetal?

poor conductor of electricity

Which of these are not the metals?

selenium, helium, and astatine

Which of the following elements are the transition metals?

silver (Ag) and tungsten (W)

Which of the following are the metals?

titanium, scandium, nickel

The oldest known metallic elements are the ones

with atomic symbols that do NOT match their modern names

What are metalloids?

elements that have some properties like metals and some like nonmetals

Which of these does not describe a metal at room temperature?

gas

Which of the following physical properties would you expect for krypton (Kr)?

gas at room temperature

Elements that are in the same ________ have a tendency to have very similar chemical properties due to periodic trends.

group

Which of the following is not the name of a chemical family?

heavy metals

Helium, He, is a nonmetallic gas and the second element in the periodic table. Rather than being placed adjacent to hydrogen, H, however, helium is placed on the far right of the table because ________.

helium is most similar to other group 18 elements

Which of the following elements are the halogens?

iodine (I) and chlorine (Cl)

Which of the following elements are the alkali metals?

lithium (Li) and potassium (K)

Use these properties to classify the substances as metals, metalloids, or nonmetals.

metals: Hg and At metalloid: Si nonmetals: S and Ne

Which of the following elements are in the same period as magnesium (Mg)?

Cl and Si

The atomic symbol for cobalt is ________.

Co

Drag the appropriate labels to their respective targets.

10 - Ne 14 - Si 16 - S 47 - Ag 80 - Hg

Which of the following images could describe an element at the atomic level?

all images

Which of the following elements are the gases at room temperature?

argon (Ar) and xenon (Xe)

Which of the following are the metalloids?

boron (5) and antimony (51)

Identify the chemical symbols corresponding to each element.

carbon- C lead - Pb antimony - Sb sodium - Na aluminum-Al

Which of these properties describes a metal?

conducts heat very well

Which of the following elements are in the fourth period?

copper and chromium