It's usually water and a type of salt take the reaction between hydrochloric acid and sodium hydroxide HCl(aq)+NaOH(aq) yeilds NaCl(aq) and H2O(l)
Answer:
The reflection of sound waves
Explanation:
An echo is a reflection of sound that bounces of of one thing to another.
Answer:
Compass - Gps
Explanation:
I belive the pro's and cons are
GPS you are trusting a little man made device
the direction you to give you directions
are going on and that it won't break or die
a device not a paper map
Compass
You can see north east south and it is usually carefully crafted for o outdoors but it has no roads and
west on the compass and if given no directions, extremely
you can see the roads follow directions confusing until you learn it
like go south then east.
Answer:
Here's what I find.
Explanation:
Iodine-131
Iodine-131 is both a beta emitter and a gamma emitter.

About 90 % of the energy is β-radiation and 10 % is γ-radiation. Both forms are highly energetic.
The main danger is from ingestion. The iodine concentrates in thyroid gland, where the β-radiation destroys cells up to 2 mm from the tissues that absorbed it.
Both the β- and γ-radiation cause cell mutations that can later become cancerous. Small doses, such as those absorbed from the nuclear disasters in the Ukraine and Japan, can cause cancers years after the original iodine has disappeared.
Plutonium-239
Plutonium-239 is an alpha emitter.

Alpha particles cannot penetrate the skin, so external exposure isn't much of a health risk.
However, they are extremely dangerous when they are inhaled and get inside cells. They travel first to the blood or lymph system and later to the bone marrow and liver, where they cause up to 1000 times more chromosomal damage than beta or gamma rays.
It takes about 20 years for plutonium to be eliminated from the liver around 50 years for from the skeleton, so it has a long time to cause damage.