Answer:
Forensic methods and techniques.
Explanation:
Forensic methods and techniques include preparing for the execution of the examination, the examination, the collection of objects and samples, the preparation of evidence for laboratory expert evaluation, the interpretation and reporting of evidence.
The purpose of these techniques is to gather evidence to establish the truth.
The main goals of forensics are the reconstruction of the crime, the identification of the suspects, the determination of the motive of the crime, the arrest of the suspect. Forensics research is based on biology, physics, and chemistry. Forensics is one of the most important categories of criminalistics today.
Answer:(4) Dust particles provide surfaces on which
water vapor can condense
Explanation:
During condensation of clouds dust particles provides spaces where water vapor may condense.
Answer:
See explanation
Explanation:
The elements in group form univalent positive ions and element in group 17 form univalent negative ions. Hence, when a group 1 element reacts with a group 17 element, a compound of the sort MX is formed. Hence, when a group 1 element reacts with bromine, a salt is formed with the general formula MBr.
Elements of group 1 are highly electro positive metals. They react with water to form the metal hydroxide and release hydrogen gas. Hence, when group 1 elements react with water, hydrogen gas is released.
A group 1 element forms a univalent positive ion while a group 16 element forms a divalent negative ion. Hence, when a groups 1 element reacts with oxygen, the compound formed must have the general formula M2O.
The reactivity of group 1 metal increases down the group hence Cs is the most reactive group 1 element.
Lithium displays a slightly different chemistry from other group 1 elements because of its small size.
Answer:
b. It exists in three different states at normal conditions in the Earth's atmosphere
Explanation:=
Snow, rain and water vapour can exist at normal conditions in the Earth's atmosphere.
a. is wrong. Only hydrogen and helium can escape Earth's atmosphere in significant amounts.
c. is wrong. The molecules of every substance are in motion even when it is solid.
d. is wrong. Other substances can form from a wide range of chemical processes.
e. is wrong. All substances expand when they become a gas.
Answer:
upper left
Explanation:
it is a trend on the periodic table. Ionization energy increases from left to right(->) I t also increases down to up
