How many significant figures are in the measurement 1400.50 km?

• 3

• 4

• 5

• 6

A mixture is

• a combination of pure substances bonded chemically

• any substance with a uniform composition

• a blend of any two or more kinds of matter, as long as each maintains its own unique properties

• any group of elements that are chemically bonded to one another

Expressed in correct scientific notation, 0.0630 m is

• 63 x 10^–3 m

• 6.3 x 10^2 m

• 6.30 x 10^–2 m

• 6.30 x 10^–4 m

Using a metric ruler with 1 mm divisions, the sides of a rectangular piece of plywood were measured as 3.0 cm and 5.55 cm. When calculating the area (l x w), a calculator shows the number 17.060

Which of these measurements shows this number rounded correctly using the rules of significant figures?

• 284 cm^2

• 280 cm^2

• 284.05 cm^2

• 300 cm^2

An experiment that tests only one factor at a time by using a comparison of a control group and an experimental group is:

• a dependent variable

• a controlled experiment

• a theory

• an independent variable

Tags

NGSS.HS-PS1-3

How many protons are present in the isotope silver-111

• 111

• 64

• 47

• 79

Most of the volume of an atom is occupied by the

• nucleus

• nuclides

• electron cloud

• protons

Mendeleev is credited with developing the first successful

• periodic table

• method for determining atomic number

• test for radioactivity

• use of X-rays

Tags

NGSS.HS-PS1-1

Elements in a group, or column, in the periodic table can be expected to have

• similar atomic masses

• similar atomic numbers

• the same number of neutrons

• similar chemical and physical properties

The electrons involved in the formation of a covalent bond are

• transferred from one atom to another

• found only in the s-orbitals

• shared valence electrons

• in filled orbitals