Question

What element they are:

1.My appearance at standard state is a silvery-white. My density when I melt is 1.46g/cm3. I burn purple, and react violently on contact with water. I see use in atomic clocks, and sometimes in glass

2.I am a diatomic molecule with a melting point of -259.14˚C and have a lower density than any other element.I am highly flammable and commonly form compounds with non-metals and halogens.I am commonly found in a product used to clean wounds and am one of the main elements involved in making stars shine

3.I am Silver-White in colour and I am so reactive I must be stored in oil.You may find me colouring glass windows in a church or reacting with water or acids to form hydrogen gas.I also oxidize and produce a film which tarnishes my Silver-White skin and can be used with other metals to form alloys

4.My soluble compounds are toxic to mammals yet I am used in paint, I am a soft but highly reactive metal. I am used in medical imaging but I am non-radioactive.

5.I am a poor conductor of heat or electricity, and my boiling point is at 536F.I am used as a fertilizer for soil and I help extinguish fire from common combustible, liquid, gas and electricity.

6.I get my name from the greek word meaning “moon”.I have 6 natural isotopes.I am protective against mercury poisoning, and my salt is used to control dandruff

7.I am a solid crystal yellow at room temperature. My melting point is , and I don’t dissolve in water I react with most elements when heatedI am famous for burning in air and producing a blue flame.I prevent rubber materials from melting, as they get warmer. I am also used to treat acne

8.I am useful inside the body and outside the body I help heal wounds. My boiling point is 184 degrees and my name is derived from my colour. A crystalline solid that gives off a coloured gas on heating and can be found in most seaweed

9.My alloy will chill out cast iron and colour ceramics. I can strengthen lead or make acids more corrosive. Some of my amino acids are fun guys but can be harmful in large groups.

10.I'm part of the p block, my standard state is a solid.
I'm a post transition metal, I'm silvery white in colour.
When evaporated i can produce a mirror as reflective as silver, my name means violet.

Answer 1

1.My appearance at standard state is a silvery-white. My density when I melt is 1.46g/cm3. I burn purple, and react violently on contact with water. I see use in atomic clocks, and sometimes in glass if silver white, then this is a "metal". if it burns/reacts violently with water, must be either alkali or alkaline eart metals. for the color test and density, this must be either potassium or cesium. Due to the atomic clock use, this msut be cesium, since units of time are based on the desintegrations of this species.

2.I am a diatomic molecule with a melting point of -259.14˚C and have a lower density than any other element.I am highly flammable and commonly form compounds with non-metals and halogens.I am commonly found in a product used to clean wounds and am one of the main elements involved in making stars shine

diatomic molecules are H, O,N,Cl,Br,I,F... if melting point i -259.15° then it must be either H,O, N. if it has the lowest density, then it must be H. if flammable --> only H and O; if it used in stars shining, then only H, choose Hydrogen.