Intro to college chemistry Quiz 04

What is the correct answer to the following expression: (86.11 - 85.49) / 28.26 ? Carry out the subtraction operation first. Record to the proper significant figures.

2.2 × 10^-2

Round the following number to 3 significant figures: 210000

2.10 × 10⁵

Perform the following calculation and answer to the correct number of significant figures: (14.32 g - 12.10 g ) / 0.2345 mL

9.47 g/mL

Calculate the following and record the answer to the proper number of significant figures. (45.68 - 45.65) x (32.1 + 89.9)

4

Round off the following to three significant figures: 0.032000000 cg

0.0320 cg

The number 14.809 rounded to three significant figures is ?

14.8

How many significant figures are in the number 6.002 × 10⁵ ?

4

Round 23456 to four significant figures.

23460

A student finds that the mass of an empty beaker is 16.600 g. She places a solid in the beaker to give a combined mass of 16.629 g. To how many significant figures is the mass of the solid known?

2 significant figures

What is the result of the following multiplication expressed in scientific notation to the correct number of significant figures ? (5.45 x 10³)(6.0 x 10^-3)

3.3 × 10¹

The result of the following calculation has how many significant figures? (0.4333 x 412.1) (33.12 – 31.12)

3 significant figures.

The density of gold is 19.3 g/mL. What is the volume of a gold nugget that weighs 79.3 g?

4.11 mL

Find the volume of an object that has a density of 3.14 g/mL and a mass of 74.0 g.

23.6 mL

Water has a density of 1.0 g/mL. Which of these objects will float in water?
Object I: mass = 50.0 g; volume = 53.1 mL
Object II: mass = 71.7 g; volume = 51.4 mL
Object III: mass = 100.0 g; volume = 50.0 mL

I only

Density is an example of a ?

Physical property.

If the density of steel is 7.85 g/cm³ and the density of rust is 5.24 g/cm³ calculate the masses of 67.6 cm³ cubes of both materials respectively (one solid cube of steel and one solid cube of rust).

531 g steel, 354 g rust

Which of the three major subatomic particles has/have a charge of –1?
i.  electron
ii. proton
iii. neutron

i only

Who discovered the ELECTRON using an experiment involving a Cathode Ray Tube?

JJ Thomson

Isotopes of an element vary in mass because of differing numbers of:

Neutrons

Which of the following is an alkali metal?

Rb