science ch.1.6

Question 1

how do we transfer a large amount of solution?

Answer 1

pour it out directly

Question 2

How do we transfer a small amount of solution?why?

Answer 2

use a dropper , Bc a dropper help us control the amount of solution to transfer more easily

Question 3

Why shouldn’t we hold a dropper upside-down?

Answer 3

The solution will go into the rubber bulb and it may be contaminated by any substance left there

Question 4

How should we mix solutions in a test tube well

Answer 4

tap the bottom of the test tube with the index finger

Question 5

who invented Bunsen burner?

Answer 5

Robert Bunsen

Question 6

What’s the use of the collar of the Bunsen burner ?

Answer 6

To control the size of the air hole

Question 7

What is the use of air hole of a Bunsen burner

Answer 7

to let air in

Question 8

What is the use of chimney of a Bunsen burner

Answer 8

to direct air and gas to the flame

Question 9

what is the use of rubber tubing of a Bunsen burner

Answer 9

to connect the Bunsen burner to the gas tap

Question 10

Should we close the air hole of the Bunsen burner after placing gas lighter above the top of chimney? yes or no?

Answer 10

no

Question 11

What is the flame called when the air hole is closed?

Answer 11

Luminous flame

Question 12

What is the flame called when the air hole is open

Answer 12

Non-luminous flame

Question 13

Two ex of the Luminous flame

Answer 13

the shape is irregular , its quiet

Question 14

two ex of Non-luminous flame

Answer 14

The shape is regular , its noisy

Question 15

which flame has an innercone

Answer 15

Non-luminous

Question 16

which part of the Non-luminous flame is the hottest and where is the coolest?

Answer 16

the tip of the inner cone is hottest , The bottom of the inner cone isn’t v hot

Question 17

three safety precaution examples

Answer 17

!. The room should be well-ventilated 2. wear safety goggles 3. Close the air hole before lighting the Bunsen burner 4. Dont fully open air hole after lighting Bunsen burner

Question 18

When doest strike back happen?

Answer 18

When the air hole is fully open

Question 19

What does a strike back look like? two features

Answer 19

A flame inside air hole , a hissing sound

Question 20

what to do when strike back happens?

Answer 20

turn off the gas tap immediately and inform the teacher

Question 21

Dont touch the chimney and collar

Answer 21

v hot

Question 22

which flame do we use for heating , why?

Answer 22

Non-luminous flame bc its hotter