There are red, blue, and white buttons in a box. The ratio of the number of red buttons to the number of white buttons is 4:7.
The ratio of the number of blue buttons to the number of red buttons
is 3:2. There are 280 white buttons.

How many buttons are there altogether?
Please help i’m very confused

680

Step-by-step explanation:

Ratio of red to white 4 : 7

Number of white = 280

White + red buttons = x

7x / 11 = 280

7x = 280 * 11

7x = 3080

x = 3080 / 7

x = 440

Number of red buttons 440 - 280 = 160

Number of red bottons ;

Blue + red buttons = x

3 : 2 ; blue : red

3 + 2 = 5 ;

2x / 5 = 160

2x = 160 * 5

2x = 800

x = 800 / 2

x = 400

Number of Blue buttons :

400 - 160 = 240

Total :

White + red + blue

280 + 160 + 240 = 680 buttons

the answer is: d) o, f, and kr.

atomic radius of bromine (br) is 114 pm.

atomic radius of oxygen (o) is 73 pm.

atomic radius of fluorine (f) is 72 pm.

atomic radius of krypron (kr) is 112 pm.

the atomic radius of a chemical element is a measure of the size of its atom.

the atomic radius varies with increasing atomic number, but usually increases because of increasing of number of electrons.

the atomic radius decreases across the periods because an increasing number of protons, because greater attraction between the protons and electrons.